Reference Guide
Colorado Hatch Calendar
What's hatching on Colorado's best trout rivers — month by month, river by river. Select a month to see what's active, which fly patterns to reach for, and whether runoff might affect conditions. Defaults to the current month.
April
SpringThis monthFront Range, Colorado
Strong BWO hatches on cloudy days (size 18-20). Caddis beginning. PMDs possible in warmer stretches. Good variety month — match what fish are eating.
Central Colorado
BWOs strong (size 18-20). Caddis beginning. Watch CFS closely — runoff can spike suddenly in April. Good fishing if you catch it right.
Pueblo County, Colorado
MOTHER'S DAY CADDIS (size 14-16) — this is the month. The Pueblo tailwater produces one of Colorado's most reliable and prolific caddis hatches in April and early May. Book the trip. Elk Hair Caddis and Graphic Caddis are your flies.
Summit County, Colorado
BWOs picking up (size 18-20). Midges and Mysis continue. One of the best spring months — stable flows while Front Range rivers begin runoff. Crowds light in early April.
Denver Metro, Colorado
BWOs active (size 18-20). Early Caddis possible. Watch flows — spring runoff can blow this small stream out quickly. Always check the gauge.
Grand County, Colorado
BWOs active (size 18-20). Caddis possible. Watch CFS closely — this big river can rise fast in April. Big water experience recommended.
Pitkin County, Colorado
BWOs active (size 18-20). Caddis beginning in lower canyon (size 14-16). Consistent tailwater flows make April one of the best months before Front Range crowds arrive.
Pitkin / Garfield County, Colorado
BWOs active (size 18-20). Caddis starting. Watch CFS — this freestone river begins rising in April from Elk Mountain snowmelt. Excellent fishing if you catch it before the rise.
Larimer County, Colorado
BWOs active (size 18-20). Caddis beginning (size 14-16). Golden Stoneflies starting in the canyon. Watch CFS — the Poudre can spike fast in April from Laramie Mountains drainage.
Gunnison County, Colorado
BWOs picking up (size 18-20). Midges active. Tailwater stability makes April excellent while freestone rivers blow out. Scenic Almont Canyon filling out with green. Pre-season crowds are low.
Gunnison / Montrose County, Colorado
BWOs strong (size 18-20). Caddis beginning. Watch CFS — this big river rises dramatically in April. Gunnison Gorge NCA access via North Rim trails. Streamers work well in higher flows.
Eagle County, Colorado
BWOs active (size 18-20). Caddis beginning. Watch CFS — Eagle blows out quickly from heavy Vail ski area snowpack. Best fishing early April before spring rise hits.
Routt County, Colorado
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — Yampa runoff can be dramatic, fed by extensive Northwest Colorado snowpack. April window is narrow but productive.
Rio Grande / Mineral County, Colorado
BWOs active (size 18-20). Caddis possible. Watch CFS — Rio Grande can begin spring rise in April from San Juan Mountains snowmelt. Good fishing if you catch the early April window.
Pitkin / Gunnison County, Colorado
BWOs active (size 18-20). Caddis beginning. Crystal River is more sensitive to runoff than larger rivers — watch CFS carefully. Upper sections near Marble blow out faster than lower.
Montezuma County, Colorado
BWOs strong (size 18-20). Caddis beginning (size 14-16). One of the best April fisheries in the state — reservoir regulation keeps flows ideal while mountain rivers start blowing out.
Jackson County, Colorado (North Park)
BWOs active (size 18-20). Caddis possible. Watch CFS — North Platte begins rising from North Park snowmelt. Good window early April before rise. Walden meadow stretch most productive.
Gunnison County, Colorado (Crested Butte)
BWOs active (size 18-20). Caddis beginning. Watch CFS — this small alpine stream blows out fast. Watch closely: when it's good in April it's very good. When it's off, wait.
Archuleta County, Colorado (Pagosa Springs)
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — San Juan drainage from Weminuche Wilderness can begin runoff in April. Green Drakes possible late April in warmer years.
La Plata County, Colorado
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — Animas drains large Weminuche Wilderness and San Juan peaks. April can spike quickly. Early April window is narrow but excellent.
Gunnison County, Colorado
BWOs active. Caddis possible. This small Gunnison County river starts rising in April from Elk Mountain and Gothic area snowpack. Catch the early April window — it's outstanding.
Grand County, Colorado (Winter Park / Tabernash)
BWOs active (size 18-20). Caddis beginning. Watch CFS carefully — Fraser rises quickly from heavy Front Range snowpack. Early April window is short. Note: gauge may underreport true flow due to Moffat diversion.
Park County, Colorado (South Park)
BWOs active (size 18-20). Caddis beginning. Watch flows from Spinney Mountain releases. South Park runoff can spike in April. Catch the pre-runoff window for exceptional dry fly fishing in open meadow country.
Eagle County, Colorado (Vail)
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — Gore Creek rises quickly from heavy Vail Pass snowpack. Early April window before the rise is narrow but often excellent.
Douglas / Jefferson County, Colorado
BWOs active (size 18-20). Caddis beginning. Upper South Platte drainage snowmelt can push flows — check Hartsel gauge proxy before committing to the 5-mile hike.
Grand County, Colorado
BWOs active (size 18-20). Caddis possible (size 14-16). Consistent tailwater flows while surrounding freestone rivers start runoff. April is one of the best months — quality fish, minimal pressure.
Grand County / Eagle County, Colorado
BWOs active. Caddis beginning (size 14-16). Watch CFS carefully — Colorado River rises dramatically in April from snowmelt. Float planning season: scout Pumphouse launch and State Bridge takeout.
Conejos County, Colorado (Rio Grande National Forest)
BWOs active. Caddis beginning (size 14-16). Watch CFS — Conejos drains significant San Juan snowpack. April window before runoff can be outstanding for wild cutthroat on BWO dries.
San Miguel County, Colorado (Telluride to Naturita)
BWOs active. Caddis beginning. Watch CFS — Wilson Peak and Telluride area snowpack can spike flows quickly in April. Golden Stonefly possible late April in canyon sections.
Hinsdale County, Colorado (Lake City)
BWOs active. Caddis possible. Watch CFS — Lake Fork drains significant Uncompahgre and San Juan snowpack. April window before runoff can be excellent. CO-149 corridor accessible with normal vehicles.
January Hatch Calendar — Colorado Fly Fishing
South Platte River — January
Midges (size 22-26) dominate. Fish midge pupa and larva sub-surface. Dry fly action rare but possible on warm afternoons with a Griffiths Gnat #22.
Arkansas River — January
Midges (size 22-26) dominate. Best action on sunny afternoons when fish move to feed. Streamer fishing can produce large browns in Salida corridor.
Arkansas River — Pueblo Tailwater — January
Tailwater flows consistent below Pueblo Reservoir year-round. Midges (size 20-26) primary. Trophy rainbows in the first 4 miles below the dam are active even in January. City Park access keeps you off ice.
Blue River — January
Midges (size 22-26) dominate all winter. Mysis shrimp imitations (size 16-20, white/cream) are effective year-round — Dillon Reservoir flushes Mysis into the tailwater constantly. One of Colorado's most reliable cold-weather fisheries.
Bear Creek — January
Small stream in winter. Fish move to deep pools. Midges (size 22-24) primary. Below 15 CFS conditions get very tough. Check gauge before driving out.
Colorado River — January
Midges (size 20-24) dominant. Big river in winter — fish deep runs and slow edges near Kremmling. Streamers productive for large browns.
Frying Pan River — January
Midges (size 20-26) dominate this tailwater year-round. Consistent flows below Ruedi hold large selective rainbows even in January — one of Colorado's best winter fisheries. Fish midge larva and pupa in slots and seams.
Roaring Fork River — January
Midges (size 20-24) primary in lower canyon near Glenwood Springs. Upper sections near Basalt fish better in winter — less icing. Streamers for large browns in deep runs.
Cache la Poudre River — January
Midges (size 22-26) dominate the canyon. Fish deep pools below Poudre Park on sunny afternoons. BWOs possible on mild days. Front Range location means milder winters than mountain streams.
Taylor River — January
World-class midge fishing year-round (size 22-28). Reservoir regulation maintains 40-50°F water all winter. Large rainbows and browns active in deep canyon pools. This is one of Colorado's premier winter fisheries.
Gunnison River — January
Midges (size 20-24) and streamers dominate. Black Canyon access is very difficult in winter. Lower river near Delta more accessible but colder. Streamers for large browns in deep runs.
Eagle River — January
Midges (size 22-26) dominate. Eagle River runs through the I-70 corridor — accessible in winter from the interstate. Fish deep pools near Minturn and Gypsum. Streamers productive for large fish.
Yampa River — January
Midges (size 20-24) and streamers dominate. Steamboat Springs section has decent winter access through town. Fish deep runs in the Fish Creek confluence area. Brown trout active in cold water.
Rio Grande — January
Midges (size 20-24) primary in the Gold Medal section. San Luis Valley winters can be brutal — temperatures well below zero possible. Fish deep pools near Wagon Wheel Gap when accessible.
Crystal River — January
Small stream in deep winter. Fish move to slow pools below Marble. Midges (size 22-24) primary. Crystal Valley road can be difficult — check conditions before heading above Redstone.
Dolores River — January
Tailwater below McPhee Reservoir maintains consistent flows year-round. Midges (size 20-24) dominant. Large rainbows and browns active in cold weather. Southwest Colorado location means milder winters than mountain rivers.
North Platte River — January
Extreme cold in North Park — temperatures well below zero common. Midges (size 22-26) when accessible near Walden. Wild brown trout in deep pools. This is remote, cold, and serious winter fishing. AWD and warm gear required.
Slate River — January
Small alpine stream in deep winter. Crested Butte receives massive snowpack — access on Slate River Road possible when plowed. Midges (size 22-24) primary. Wild fish dormant in deep pools.
San Juan River — January
Midges (size 20-24) primary through Pagosa Springs Riverwalk. Pagosa has a mild mountain climate — warmer than northern Colorado. Wild rainbows and browns active in slower stretches below town.
Animas River — January
Midges (size 20-24) primary through Durango. Animas flows through downtown — city park access year-round. Wild browns in deep pools below the Lightner Creek confluence. Streamers productive for larger fish.
East River — January
Small freestone river in deep winter. Gothic and upper sections inaccessible. Midges (size 22-24) in slow pools near Crested Butte. Wild cutthroat and browns dormant in deep runs. CB access only.
Fraser River — January
Midges (size 22-26) primary. Fraser runs along US-40 — road access good but cold. Grand County winters are extreme. Wild browns in deep pools near Tabernash. Moffat Tunnel diversion reduces gauge readings vs. actual flow.
Dream Stream — January
Midges (size 22-26) primary on this flat meadow water. January Dream Stream is for the committed — South Park at 9,000 ft in winter is brutally cold. Fish slow runs with long leaders and 6-7X tippet. Trophy browns active on sunny afternoons.
Gore Creek — January
Midges (size 22-26) primary through Vail village. Gore Creek accessible year-round via the paved rec path — unique in Colorado. Cold alpine winter at 8,150 ft but the urban stretch stays open. Most of the valley is skiing in January.
Cheesman Canyon — January
Midges (size 22-26) on remote canyon water. The 5-mile hike on Gill Trail (#610) deters virtually all winter visitors — complete solitude in January. Fish slow pools and seams with long leaders. Cheesman is for the committed.
Williams Fork River — January
Midges (size 22-26) below Williams Fork Reservoir — one of Colorado's least-fished winter tailwaters. Quality brown trout with essentially zero competition. Reservoir regulation means consistent cold water year-round.
Colorado River — Gold Medal — January
Midges (size 20-24) and streamer fishing for large browns in the deep holes. This is float territory in winter — wade access is minimal. Big attractor streamers in the slow edges and eddies. Runoff season still months away.
Conejos River — January
Midges (size 22-26) primary. Conejos River in January is remote and cold — San Luis Valley and Conejos County winters are serious. Wild Rio Grande Cutthroat dormant in deep pools. Access via CO-17 requires checking road conditions.
San Miguel River — January
Midges (size 22-26) primary. Upper Telluride sections (8,750 ft) are cold and potentially iced over. Lower canyon sections near Norwood and Naturita more accessible. San Miguel in January is a remote winter adventure.
Lake Fork of the Gunnison — January
Midges (size 22-26) primary. Lake City and the Lake Fork in January is extreme — Lake San Cristobal area is remote and cold. Fish deep pools below the lake outlet. Virtually no angling pressure December through March.
February Hatch Calendar — Colorado Fly Fishing
South Platte River — February
Midges remain primary. First Blue-Winged Olives (BWO) appear on cloudy overcast days (size 20-22). Watch for surface feeding around midday.
Arkansas River — February
Midges year-round. BWOs beginning on warm/overcast days (size 20-22). Salida stretch has consistent winter midge action.
Arkansas River — Pueblo Tailwater — February
Midges continue (size 20-26). BWOs emerging on warm/overcast afternoons (size 20-22). Pueblo has a milder climate than mountain rivers — February is fishable when Front Range streams are frozen.
Blue River — February
Midges continue (size 22-26). BWOs possible on overcast days (size 20-22). Mysis shrimp always a fallback. Flows stable below Dillon Dam — the Blue fishes when every other Summit County water is iced over.
Bear Creek — February
Midges continue. Stream waking up on warm days. BWOs possible on overcast afternoons (size 20-22). Small water, small flies, light tippet.
Colorado River — February
Midges continue. BWOs possible on warm/cloudy days (size 20-22). Kremmling corridor has consistent winter midge action.
Frying Pan River — February
Midges primary (size 20-26). BWOs possible on overcast days (size 20-22). Large rainbows require 6X tippet and precise drifts. The Pan fishes when every other river is iced up.
Roaring Fork River — February
Midges continue. BWOs possible on warm/overcast days (size 20-22). Basalt section most reliable access in February. Upper Fork near Aspen can be iced over.
Cache la Poudre River — February
Midges continue. BWOs picking up on warm/cloudy days (size 20-22). The Poudre fishes when mountain rivers are locked up — a key Front Range winter option for Fort Collins anglers.
Taylor River — February
Midges (size 22-28) dominant. Reservoir keeps flows stable and temperatures consistent. One of Colorado's top winter tailwaters — fish are numerous and large. 6X tippet required.
Gunnison River — February
Midges continue. BWOs possible on warm/overcast days (size 20-22). Gunnison holds trophy-sized fish year-round but access requires planning. Gorge trails may be icy.
Eagle River — February
Midges continue. BWOs beginning on mild/cloudy days (size 20-22). Eagle sees heavy pressure near Vail/Avon but far less downstream toward Gypsum. February is a good time to explore lower sections.
Yampa River — February
Midges continue. BWOs possible on mild/overcast days (size 20-22). Lower Yampa near Craig sees less pressure than Steamboat and can produce well in late winter.
Rio Grande — February
Midges continue. BWOs possible on warm/sunny afternoons (size 20-22). South Fork section near Wagon Wheel Gap has better winter access than upper Creede reach. Worth the long drive if conditions cooperate.
Crystal River — February
Midges continue. BWOs possible on warm/cloudy days (size 20-22). Crystal fishes well in February when accessible. Carbondale section most reliable winter access.
Dolores River — February
Midges continue. BWOs possible on overcast days (size 20-22). McPhee tailwater is one of Southwest Colorado's best winter fisheries. Cortez/Dolores area accessible when northern rivers are frozen.
North Platte River — February
Midges continue. BWOs possible on rare mild/overcast days. North Park begins warming in late February but remains cold. The Walden meadows are most accessible in winter. Northgate Canyon too remote for most in February.
Slate River — February
Midges continue. BWOs possible on sunny afternoons (size 20-22). Slate River Rd improves in late February. Small stream patience required — fish spook easily in cold clear water.
San Juan River — February
Midges continue. BWOs possible on warm afternoons (size 20-22). Pagosa Springs is accessible year-round — the West Fork section above town remains fishable in mild winters.
Animas River — February
Midges continue. BWOs possible on mild/overcast days (size 20-22). Durango's mild La Plata County climate makes February fishing more comfortable than northern Colorado. Gold Medal section accessible year-round.
East River — February
Midges continue. BWOs possible on sunny afternoons (size 20-22). Lower sections near Almont and CB South more accessible than upper Gothic reach in February.
Fraser River — February
Midges continue. BWOs possible on mild overcast days (size 20-22). Fraser Valley warms slightly. Pre-runoff fishing can be good in late February if Moffat diversion is running low.
Dream Stream — February
Midges continue (size 22-26). BWOs possible on mild overcast days (size 20-22). South Park's cold, arid climate means February is challenging but uncrowded. Long leaders essential on flat meadow water — fish can see you from 40 feet.
Gore Creek — February
Midges continue (size 22-26). BWOs possible on warm/overcast afternoons (size 20-22). February on Gore Creek is lightly fished — resort town is focused on the mountain, not the stream. Enjoy the solitude.
Cheesman Canyon — February
Midges continue (size 22-26). BWOs possible on warm afternoons (size 20-22). February on Cheesman Canyon: quality fish, zero competition. Clear water demands 7X tippet even in cold conditions.
Williams Fork River — February
Midges continue. BWOs possible on overcast days (size 20-22). Williams Fork in February: reliable fishing in Grand County while everyone else is at the Blue River or Frying Pan. Verify current access maps.
Colorado River — Gold Medal — February
Midges continue. BWOs possible on overcast days (size 20-22). Streamer fishing productive in winter flows. Float fishing not common in February but the wade access at Pumphouse can be productive on mild days.
Conejos River — February
Midges continue. BWOs possible on mild afternoons (size 20-22). February on the Conejos is virtually unpressured. Wild cutthroat in their stronghold. Platoro area may require chains or AWD for upper access.
San Miguel River — February
Midges continue. BWOs possible on mild days. Telluride ski season means the upper river sees zero fishing pressure. Lower Norwood section most accessible. Mountain roads — check conditions.
Lake Fork of the Gunnison — February
Midges continue. BWOs possible on mild/overcast days (size 20-22). Lake Fork in February: cold, remote, and surprisingly productive for the dedicated angler who makes the 3+ hour drive from Denver.
March Hatch Calendar — Colorado Fly Fishing
South Platte River — March
BWOs picking up strongly on overcast days (size 18-22). Midges still active. Best action 10am-2pm during hatches. Parachute BWO or Sparkle Dun.
Arkansas River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window can be excellent if flows stable. Check gauge before driving — runoff starts in late March some years.
Arkansas River — Pueblo Tailwater — March
BWOs picking up (size 18-20). Midges active. Pre-caddis window. Reservoir regulation means flows stay consistent regardless of snowmelt upstream. March is excellent on the Pueblo tailwater.
Blue River — March
BWOs starting on cloudy days (size 20-22). Midges year-round. Mysis imitations remain effective. Reservoir regulation means consistent flows regardless of upstream snowpack.
Bear Creek — March
BWOs beginning (size 18-20). Midges active. Pre-runoff window can be excellent on this beginner-accessible stream near Denver.
Colorado River — March
BWOs starting (size 18-20). Midges active. Pre-runoff window — catch it before snowmelt starts. Big water, big fish, requires wading caution.
Frying Pan River — March
BWOs picking up strongly on cloudy days (size 18-20). Midges year-round. Ruedi Reservoir regulation means consistent flows regardless of snowpack — catch the pre-runoff window.
Roaring Fork River — March
BWOs picking up on overcast days (size 18-20). Midges active. Pre-runoff March window can be outstanding on the Basalt section — catch it before snowmelt begins.
Cache la Poudre River — March
BWOs strong on overcast days (size 18-20). Midges active. Pre-runoff window can be excellent — March on the Poudre before snowmelt is often overlooked and very productive.
Taylor River — March
Midges year-round. BWOs possible on overcast days (size 20-22). Taylor Park is still cold in March — dress for mountain winter. Consistent flows regardless of upstream snowpack.
Gunnison River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window — Black Canyon access from East Portal opens as weather improves. March can be excellent before runoff builds.
Eagle River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff March window is often excellent. Vail Pass snowpack will push flows in weeks — catch the Eagle before it rises.
Yampa River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff fishing can be excellent in March. Yampa Valley warming up — catch it before Flattops and Rabbit Ears snowmelt arrives.
Rio Grande — March
BWOs starting (size 18-20). Midges active. Pre-runoff window can be outstanding in the upper Gold Medal section. March Rio Grande is seriously underutilized.
Crystal River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window on this smaller stream. March can be excellent for clear-water nymphing before Elk Mountain snowmelt starts.
Dolores River — March
BWOs picking up (size 18-20). Midges active. Tailwater stability makes March excellent. Pre-runoff window while freestone rivers are still sketchy. An early-season gem.
North Platte River — March
BWOs starting (size 18-20). Midges active. Pre-runoff window can be excellent — March on the North Platte headwaters is underutilized. Wild browns in North Park meadow stretches feeding actively.
Slate River — March
BWOs picking up on cloudy days (size 18-20). Midges active. Pre-runoff window brief but productive. Catch the Slate before Elk Mountain snowmelt starts — March can be excellent.
San Juan River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window excellent through Pagosa Riverwalk access. March San Juan is an underutilized gem in Southwest Colorado.
Animas River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window excellent — March Animas before San Juan snowmelt is outstanding. Gold Medal stretch through Durango at its most manageable.
East River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window brief but excellent. East River has excellent wild cutthroat that respond aggressively in March before snowmelt.
Fraser River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window — catch the Fraser before Winter Park and Berthoud Pass snowmelt starts. March is often the best month before runoff.
Dream Stream — March
BWOs picking up on overcast days (size 18-20). Midges active. March pre-runoff window can be excellent — catch the Dream Stream before South Park snowmelt begins. 12-14 ft leaders and 6X minimum.
Gore Creek — March
BWOs picking up (size 18-20). Midges active. Pre-runoff March window can be excellent — catch Gore Creek before Vail Pass and Ten Mile Range snowmelt begins building flows.
Cheesman Canyon — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window — Cheesman Canyon in March before South Park snowmelt is exceptional. The hike is worth it. 6-7X tippet, precise presentations required.
Williams Fork River — March
BWOs picking up (size 20-22). Midges active. Pre-runoff window — access may still be limited by road conditions. Williams Fork tailwater stays fishable while surrounding drainages begin building.
Colorado River — Gold Medal — March
BWOs starting (size 18-20). Midges active. Pre-runoff window — Pumphouse wade access at its best before spring flows build. Big river brown trout feeding. Plan floats soon before runoff makes it dangerous.
Conejos River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window — catch the Conejos before San Juan Mountains snowmelt begins. Wild Rio Grande Cutthroat feeding actively in March. Use barbless hooks.
San Miguel River — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window. San Miguel Mountain snowmelt will arrive — catch the spring window before it builds. Upper Telluride section can be excellent in March.
Lake Fork of the Gunnison — March
BWOs picking up (size 18-20). Midges active. Pre-runoff window — catch the Lake Fork before Lake San Cristobal watershed snowmelt begins. Wild brown trout feeding actively in March.
April Hatch Calendar — Colorado Fly Fishing
South Platte River — April
Strong BWO hatches on cloudy days (size 18-20). Caddis beginning. PMDs possible in warmer stretches. Good variety month — match what fish are eating.
Arkansas River — April
BWOs strong (size 18-20). Caddis beginning. Watch CFS closely — runoff can spike suddenly in April. Good fishing if you catch it right.
Arkansas River — Pueblo Tailwater — April
MOTHER'S DAY CADDIS (size 14-16) — this is the month. The Pueblo tailwater produces one of Colorado's most reliable and prolific caddis hatches in April and early May. Book the trip. Elk Hair Caddis and Graphic Caddis are your flies.
Blue River — April
BWOs picking up (size 18-20). Midges and Mysis continue. One of the best spring months — stable flows while Front Range rivers begin runoff. Crowds light in early April.
Bear Creek — April
BWOs active (size 18-20). Early Caddis possible. Watch flows — spring runoff can blow this small stream out quickly. Always check the gauge.
Colorado River — April
BWOs active (size 18-20). Caddis possible. Watch CFS closely — this big river can rise fast in April. Big water experience recommended.
Frying Pan River — April
BWOs active (size 18-20). Caddis beginning in lower canyon (size 14-16). Consistent tailwater flows make April one of the best months before Front Range crowds arrive.
Roaring Fork River — April
BWOs active (size 18-20). Caddis starting. Watch CFS — this freestone river begins rising in April from Elk Mountain snowmelt. Excellent fishing if you catch it before the rise.
Cache la Poudre River — April
BWOs active (size 18-20). Caddis beginning (size 14-16). Golden Stoneflies starting in the canyon. Watch CFS — the Poudre can spike fast in April from Laramie Mountains drainage.
Taylor River — April
BWOs picking up (size 18-20). Midges active. Tailwater stability makes April excellent while freestone rivers blow out. Scenic Almont Canyon filling out with green. Pre-season crowds are low.
Gunnison River — April
BWOs strong (size 18-20). Caddis beginning. Watch CFS — this big river rises dramatically in April. Gunnison Gorge NCA access via North Rim trails. Streamers work well in higher flows.
Eagle River — April
BWOs active (size 18-20). Caddis beginning. Watch CFS — Eagle blows out quickly from heavy Vail ski area snowpack. Best fishing early April before spring rise hits.
Yampa River — April
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — Yampa runoff can be dramatic, fed by extensive Northwest Colorado snowpack. April window is narrow but productive.
Rio Grande — April
BWOs active (size 18-20). Caddis possible. Watch CFS — Rio Grande can begin spring rise in April from San Juan Mountains snowmelt. Good fishing if you catch the early April window.
Crystal River — April
BWOs active (size 18-20). Caddis beginning. Crystal River is more sensitive to runoff than larger rivers — watch CFS carefully. Upper sections near Marble blow out faster than lower.
Dolores River — April
BWOs strong (size 18-20). Caddis beginning (size 14-16). One of the best April fisheries in the state — reservoir regulation keeps flows ideal while mountain rivers start blowing out.
North Platte River — April
BWOs active (size 18-20). Caddis possible. Watch CFS — North Platte begins rising from North Park snowmelt. Good window early April before rise. Walden meadow stretch most productive.
Slate River — April
BWOs active (size 18-20). Caddis beginning. Watch CFS — this small alpine stream blows out fast. Watch closely: when it's good in April it's very good. When it's off, wait.
San Juan River — April
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — San Juan drainage from Weminuche Wilderness can begin runoff in April. Green Drakes possible late April in warmer years.
Animas River — April
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — Animas drains large Weminuche Wilderness and San Juan peaks. April can spike quickly. Early April window is narrow but excellent.
East River — April
BWOs active. Caddis possible. This small Gunnison County river starts rising in April from Elk Mountain and Gothic area snowpack. Catch the early April window — it's outstanding.
Fraser River — April
BWOs active (size 18-20). Caddis beginning. Watch CFS carefully — Fraser rises quickly from heavy Front Range snowpack. Early April window is short. Note: gauge may underreport true flow due to Moffat diversion.
Dream Stream — April
BWOs active (size 18-20). Caddis beginning. Watch flows from Spinney Mountain releases. South Park runoff can spike in April. Catch the pre-runoff window for exceptional dry fly fishing in open meadow country.
Gore Creek — April
BWOs active (size 18-20). Caddis starting (size 14-16). Watch CFS — Gore Creek rises quickly from heavy Vail Pass snowpack. Early April window before the rise is narrow but often excellent.
Cheesman Canyon — April
BWOs active (size 18-20). Caddis beginning. Upper South Platte drainage snowmelt can push flows — check Hartsel gauge proxy before committing to the 5-mile hike.
Williams Fork River — April
BWOs active (size 18-20). Caddis possible (size 14-16). Consistent tailwater flows while surrounding freestone rivers start runoff. April is one of the best months — quality fish, minimal pressure.
Colorado River — Gold Medal — April
BWOs active. Caddis beginning (size 14-16). Watch CFS carefully — Colorado River rises dramatically in April from snowmelt. Float planning season: scout Pumphouse launch and State Bridge takeout.
Conejos River — April
BWOs active. Caddis beginning (size 14-16). Watch CFS — Conejos drains significant San Juan snowpack. April window before runoff can be outstanding for wild cutthroat on BWO dries.
San Miguel River — April
BWOs active. Caddis beginning. Watch CFS — Wilson Peak and Telluride area snowpack can spike flows quickly in April. Golden Stonefly possible late April in canyon sections.
Lake Fork of the Gunnison — April
BWOs active. Caddis possible. Watch CFS — Lake Fork drains significant Uncompahgre and San Juan snowpack. April window before runoff can be excellent. CO-149 corridor accessible with normal vehicles.
May Hatch Calendar — Colorado Fly Fishing
South Platte River — May
BWOs continue. Caddis (size 16-18) becoming active at dusk (Elk Hair Caddis). PMDs starting (size 16-18). Peak early-season variety.
Arkansas River — May
RUNOFF SEASON STARTING — CFS rising rapidly toward unfishable levels. Caddis (size 14-16) beginning heavy emergence. Check gauge every day.
Arkansas River — Pueblo Tailwater — May
Caddis (size 14-16) continuing into early May. PMDs starting (size 16-18). Tricos possible in slower sections. Tailwater stability means flows stay fishable while the upper Arkansas is in full runoff.
Blue River — May
BWOs active. Caddis beginning (size 14-16). TAILWATER ADVANTAGE — while Arkansas and South Platte blow out, Blue River flows stay fishable. Mysis year-round.
Bear Creek — May
RUNOFF RISK — small stream, very sensitive to snowmelt. CFS can spike fast and stay unfishable for weeks. Check gauge every single time.
Colorado River — May
RUNOFF SEASON — CFS rising toward unfishable wading levels. Float fishing possible at higher flows. Check back in late June or July.
Frying Pan River — May
BWOs and Caddis both emerging (size 14-16). PMDs starting (size 16-18). TAILWATER ADVANTAGE — while South Platte and Arkansas blow out, Frying Pan stays fishable and at its best.
Roaring Fork River — May
RUNOFF STARTING — CFS rising on upper sections. Lower near Glenwood may hold longer. Caddis (size 14-16) active when flows allow. Check gauge before driving from Denver.
Cache la Poudre River — May
RUNOFF RISK — CFS rising from Mummy Range snowmelt. Caddis (size 14-16) and Golden Stoneflies (size 8-12) active during flow windows. Below Joe Wright Reservoir section more stable.
Taylor River — May
BWOs and PMDs starting (size 16-18). Caddis (size 14-16) possible. TAILWATER ADVANTAGE — Taylor stays fishable through runoff season when Gunnison and Arkansas are blown.
Gunnison River — May
RUNOFF SEASON — heavy drainage from Elk Mountains and Blue Mesa. Caddis emerging during lower windows. The Gorge section may be blown out. Float anglers only in high water.
Eagle River — May
RUNOFF RISK — CFS rising rapidly from Vail Pass snowmelt. Caddis (size 14-16) and stoneflies active during lower flow windows. Check the Minturn gauge before making the I-70 drive.
Yampa River — May
RUNOFF SEASON — CFS rising rapidly. Yampa can run very high. Caddis hatching during flow windows. Salmonfly (Pteronarcys californica, size 4-8) beginning late May — one of the most exciting hatches in Colorado.
Rio Grande — May
RUNOFF SEASON — CFS rising rapidly. Rio Grande headwaters drain enormous San Juan Mountains snowpack — flows can exceed 3,000 CFS. Check gauge before the long drive from Denver.
Crystal River — May
RUNOFF RISK — small crystal-clear stream becomes high and turbid with heavy snowmelt from Elk Mountains. Check Redstone gauge before driving through Carbondale on Hwy 133.
Dolores River — May
BWOs and Caddis both active. TAILWATER ADVANTAGE — Dolores stays fishable during runoff season when other Southwest Colorado rivers are blown. McPhee releases are consistent.
North Platte River — May
RUNOFF SEASON — CFS rising from North Park and Rawah Wilderness snowpack. Caddis and stoneflies active during windows. Northgate Canyon may be inaccessible — check road conditions off CO-127.
Slate River — May
HEAVY RUNOFF — Crested Butte receives some of the highest snowpack in Colorado. Slate runs high and turbid most of May. Check back in late June. Patience pays off.
San Juan River — May
RUNOFF SEASON — Weminuche Wilderness snowpack is substantial. CFS rising rapidly. Pagosa Riverwalk may hold longer than upper forks. Check flows before the drive from Durango.
Animas River — May
RUNOFF SEASON — heavy San Juan snowpack drainage. Animas can run very high and turbid. Downtown Durango section may stay lower longest. Check gauge before driving — runoff can be dramatic.
East River — May
HEAVY RUNOFF — Crested Butte and Gothic receive extreme snowpack. East River runs high and turbid from late April through much of May. Wait for July. Check Almont gauge.
Fraser River — May
RUNOFF SEASON — CFS rising fast. Windy Gap and Moffat Tunnel diversion operations may affect both gauge readings and actual river levels. Check the river visually if possible before wading.
Dream Stream — May
RUNOFF RISK — Tarryall and Fourmile Creek snowmelt affects flows. Spinney and Eleven Mile reservoirs buffer variability somewhat. PMDs starting (size 16-18) on warm days. Check Hartsel gauge before making the drive.
Gore Creek — May
RUNOFF RISK — CFS rising fast from Vail Pass drainage. Caddis (size 14-16) and Golden Stonefly active during flow windows. Check gauge before making the I-70 drive.
Cheesman Canyon — May
RUNOFF RISK — South Park and Cheesman Reservoir drainage can spike flows. Some years the canyon stays fishable longer than other SP sections. Verify before making the hike.
Williams Fork River — May
BWOs and Caddis both active. TAILWATER ADVANTAGE — Williams Fork stays fishable when surrounding Grand County rivers blow out. Check CPW access maps — some sections require verification.
Colorado River — Gold Medal — May
RUNOFF SEASON — CFS rising rapidly from extensive Colorado River basin snowpack. Float fishing possible at higher flows with experienced guides. Check gauge every day. Do not wade at high water on this river.
Conejos River — May
RUNOFF SEASON — San Juan Mountains snowmelt pushes flows high. Platoro Reservoir area may fish earlier than lower sections. Check Mogote gauge before the 4+ hour drive from Denver.
San Miguel River — May
RUNOFF SEASON — Heavy San Juan and Telluride-area snowpack. CFS rising. Lower canyon sections near Naturita may clear faster than upper. Golden Stonefly (size 8-12) when flows settle.
Lake Fork of the Gunnison — May
RUNOFF SEASON — Lake Fork CFS rising from snowmelt. Flows can be high and turbid. Check Gateview gauge before making the long drive. Lower sections near Gateview may clear faster.
June Hatch Calendar — Colorado Fly Fishing
South Platte River — June
Caddis heavy in evenings (size 14-16). PMDs (size 16-18) mid-morning 9-11am. Midges always. Golden Stoneflies possible. Best variety month of the year.
Arkansas River — June
Peak runoff — flows often 2,000+ CFS and unfishable for wading. Caddis hatching when flows allow. Check back in mid-to-late July for prime summer fishing.
Arkansas River — Pueblo Tailwater — June
Caddis evening action tapering. PMDs (size 16-18) mid-morning. Tricos (size 22-24) possible early morning. Summer heat can warm water in Pueblo — fish early morning or evening. Below-dam section stays cooler.
Blue River — June
Caddis (size 14-16) evenings. PMDs possible (size 16-18). Tailwater stays consistent when other rivers blow out. Silverthorne section fishing well. Mysis imitations as backup always.
Bear Creek — June
Caddis active (size 14-16) when flows settle. Yellow Sally Stoneflies (size 14) — look for them on warm afternoons. Fun accessible dry fly fishing near Denver.
Colorado River — June
Peak runoff — often 5,000-10,000+ CFS. Dangerous for wading. Float trips possible with a guide. Check back mid-July for prime conditions.
Frying Pan River — June
Caddis (size 14-16) evenings. PMDs (size 16-18) mid-morning. Technical fishing — these rainbows have seen every pattern. Use 6X minimum, precise dead drifts. Pale Evening Duns possible.
Roaring Fork River — June
Peak runoff on upper Fork. Lower canyon near Glenwood may settle first. Caddis hatching when flows settle. Post-runoff July is often the best month of the year on the Fork.
Cache la Poudre River — June
Variable flows — canyon may still be running high early June. Caddis heavy (size 14-16). Golden Stonefly and Yellow Sally (size 14) active. Check flows before driving Poudre Canyon Hwy.
Taylor River — June
PMDs (size 16-18) and Caddis (size 14-16) both active. Consistent tailwater flows. Long days in the canyon. Water temp optimal for surface feeding. Prime Taylor conditions.
Gunnison River — June
Peak runoff — flows often too high and turbid for most wading. Lower river near Delta may settle faster. Check gauge daily. Excellent post-runoff fishing begins in July.
Eagle River — June
Variable runoff — flows elevated well into June some years. Caddis (size 14-16) and Golden Stoneflies when settled. Lower Eagle near Wolcott and Gypsum tends to settle before upper sections.
Yampa River — June
Runoff continuing through June. Salmonfly and Golden Stonefly (size 6-10) emerging when flows settle — if you can time this, it's extraordinary fishing with large aggressive trout. Craig section may settle before Steamboat.
Rio Grande — June
Peak runoff — Gold Medal section often unfishable through most of June. Lower section near Del Norte sometimes holds. Check gauge daily — post-runoff July is outstanding.
Crystal River — June
Variable — flows often too high early June. Caddis and Yellow Sally Stoneflies (size 14) active when settled. Lower sections near Carbondale clear and become fishable before upper reaches.
Dolores River — June
Caddis (size 14-16) active. PMDs possible (size 16-18). McPhee water releases for irrigation can affect flows — watch the gauge. When flows are right, June can be outstanding.
North Platte River — June
Variable runoff — Gold Medal Northgate Canyon may still be running high early June. Golden Stoneflies (size 8-12) and caddis emerging when settled. Check Walden gauge before committing to the drive.
Slate River — June
Flows settling mid-to-late June. Yellow Sally Stoneflies (size 14) active. Caddis hatching. Small stream character — use 5X or 6X, approach carefully, make short casts to holding lies.
San Juan River — June
Peak runoff — main stem often blown out. West and East Forks above Pagosa may clear faster. Post-runoff late June can be excellent. Golden Stonefly (size 8-12) beginning when flows settle.
Animas River — June
Peak runoff — Gold Medal section often blown out June. Float fishing possible at high water with a guide. Check back in late June or July for prime wade conditions.
East River — June
Flows settling mid-to-late June. Caddis beginning (size 14-16). Golden Stonefly possible. East River below Cement Creek clears before upper Gothic sections. Lower beats fish first.
Fraser River — June
Peak runoff on the Fraser. Caddis hatching when flows settle. Lower Fraser near Granby may clear before Winter Park sections. Post-runoff July is the best fishing month of the year.
Dream Stream — June
PMDs (size 16-18) hatching. Caddis (size 14-16) evenings. Post-runoff June can be outstanding. Spring spawning fish from Spinney Mountain adding trophy trout to the reach. Flat water rewards stealth.
Gore Creek — June
Variable runoff — flows may still be elevated early June. Caddis (size 14-16) and stoneflies when settled. Post-runoff late June opens up quickly. Summer tourist season beginning.
Cheesman Canyon — June
Variable — flows may still be elevated early June. Caddis (size 14-16) when settled. Post-runoff June opens for technical summer fishing. Gill Trail (#610) from the trailhead.
Williams Fork River — June
Caddis (size 14-16) active. PMDs possible (size 16-18). Post-runoff surrounding watershed improves water clarity throughout the valley. Good small-stream dry fly fishing beginning.
Colorado River — Gold Medal — June
Peak runoff — flows often 3,000-8,000+ CFS. Float fishing with a guide only at these levels. Check gauge daily. Post-runoff July begins the prime fishing season for the Gold Medal stretch.
Conejos River — June
Variable — flows settling through June. Caddis (size 14-16) and stoneflies active when settled. Post-runoff June can be excellent. Rio Grande National Forest access via CO-17. Bring the RGNF map.
San Miguel River — June
Flows settling mid-to-late June. Caddis (size 14-16) active. Golden Stonefly when settled. Post-runoff June opens the canyon sections for dry fly fishing. Upper Telluride excellent when accessible.
Lake Fork of the Gunnison — June
Variable — flows settling through June. Caddis (size 14-16) when settled. Post-runoff June on the Lake Fork opens the summer season. Lake City area beautiful in early summer.
July Hatch Calendar — Colorado Fly Fishing
South Platte River — July
PMDs dominant (size 16-18) hatching 9-11am — Parachute PMD or Sparkle Dun. Caddis at dusk. Tricos (size 20-24) early morning on slower stretches. Terrestrials starting.
Arkansas River — July
Flows dropping post-runoff — prime fishing window opening. Caddis (size 14-16) active. PMDs (size 16-18) beginning mid-morning. Gold Medal water at its best.
Arkansas River — Pueblo Tailwater — July
PMDs (size 16-18) mid-morning. Tricos (size 22-24) early morning. Terrestrials (ants, beetles, small hoppers) mid-day. Fish early to beat afternoon heat. First 2 miles below dam are coolest in summer.
Blue River — July
PMDs (size 16-18) mid-morning. Caddis evenings. Mysis shrimp year-round — especially effective when nothing appears to be hatching. Summer weekend crowds — fish early morning or evening.
Bear Creek — July
Yellow Sally Stoneflies (size 14). Caddis (size 14-16). Terrestrials (ants #18, beetles) mid-day. Summer prime time if flows are 20-80 CFS sweet spot.
Colorado River — July
Post-runoff flows dropping. PMDs (size 14-16) emerging. Caddis (size 14-16). Green Drakes (size 10-12) BEGINNING — watch for this iconic hatch.
Frying Pan River — July
PMDs dominant (size 16-18) hatching 9-11am — Parachute PMD or Sparkle Dun. Caddis at dusk. Fish are extremely selective in summer. Smaller fly and finer tippet often wins.
Roaring Fork River — July
Post-runoff prime season. PMDs (size 16-18) mid-morning. Caddis evenings (Elk Hair Caddis). Upper Fork near Aspen excellent. Green Drakes (size 10-12) possible in July.
Cache la Poudre River — July
Prime fishing post-runoff. PMDs (size 16-18) mid-morning. Caddis evenings. Yellow Sally Stoneflies (size 14). Wild trout in the Gold Medal section above Rustic. One of the Poudre's best months.
Taylor River — July
PMDs dominant (size 16-18) morning hatches. Caddis evenings. Large selective trout require precise presentations — 5X minimum, technical dead drifts. This is the Taylor at full glory.
Gunnison River — July
Post-runoff prime time. Green Drakes (size 10-12) emerging — Gunnison is one of Colorado's premier Green Drake rivers. PMDs (size 16-18). Caddis evenings. Pack in via Gorge trails.
Eagle River — July
Post-runoff prime time. PMDs (size 16-18) mid-morning. Caddis evenings (Elk Hair Caddis). Golden Stoneflies still possible early July. Good hatches near Gypsum that most anglers ignore.
Yampa River — July
Post-runoff prime time. Caddis (size 14-16) heavy. PMDs (size 16-18) morning. Salmonfly late stragglers possible early July. The Yampa in July is at its best and sees a fraction of Front Range pressure.
Rio Grande — July
Post-runoff prime time. Caddis (size 14-16) active. PMDs (size 16-18). Streamer fishing for large browns. Gold Medal section near Wagon Wheel Gap at its absolute best in July.
Crystal River — July
Prime dry fly season. Caddis (size 14-16) evenings. Yellow Sally Stoneflies (size 14) mid-afternoon. PMDs (size 16-18) possible. Stunning canyon setting, wild trout, minimal pressure.
Dolores River — July
PMDs (size 16-18) mid-morning. Caddis evenings. Terrestrials productive. Summer fishing depends on McPhee reservoir release levels — check CFS before making the long drive from Durango.
North Platte River — July
Prime fishing post-runoff. Caddis (size 14-16) evenings. PMDs (size 16-18) mid-morning. Golden Stonefly stragglers possible. Northgate Canyon Gold Medal section open — artificial flies and lures only. Wild browns are exceptional.
Slate River — July
Prime small-stream dry fly season. Caddis (size 14-16) evenings. Yellow Sally Stonefly (size 14). PMDs (size 16-18). Wild browns, rainbows, and brook trout in classic alpine pocket water. Crested Butte's best month.
San Juan River — July
Post-runoff prime time. Caddis (size 14-16) heavy in evenings. Green Drakes (size 10-12) possible through the Pagosa canyon stretch — one of the more reliable Southwest Colorado Green Drake rivers. PMDs mid-morning.
Animas River — July
Post-runoff prime time. Caddis (size 14-16) heavy evenings. PMDs (size 16-18) mid-morning. Golden Stoneflies possible early July. Gold Medal from Lightner Creek to Purple Cliffs fishes exceptionally well.
East River — July
Prime season. Caddis (size 14-16) evenings. PMDs (size 16-18). Green Drakes possible (size 10-12) — East River is one of the better small-stream Green Drake waters in the Gunnison drainage. Wild cutthroat respond to big dry flies.
Fraser River — July
Post-runoff prime time. PMDs (size 16-18) mid-morning. Caddis evenings (Elk Hair Caddis). Wild brown trout in the US-40 corridor reach. St. Louis Creek Campground is the primary access point.
Dream Stream — July
PMDs dominant (size 16-18) morning. Caddis evenings. Terrestrials (ants #18-20) starting. Summer crowds peak — arrive before 7am for the best water. Afternoon wind on the open meadow makes presentations challenging.
Gore Creek — July
PMDs (size 16-18) mid-morning. Caddis evenings. GREEN DRAKES (size 10-12) possible — Gore Creek is known for its Green Drake hatch in summer. Walk east toward East Vail on the rec path for solitude. Summer crowds peak near town.
Cheesman Canyon — July
PMDs (size 16-18) mid-morning. Caddis evenings. The 5-mile hike deters crowds — fish are noticeably less pressured than any other Gold Medal South Platte section. Terrestrials effective on canyon walls.
Williams Fork River — July
PMDs mid-morning (size 16-18). Caddis evenings. Terrestrials mid-day. Williams Fork in July has almost no competition — most Grand County anglers are on the Colorado River or Blue. Consistently productive.
Colorado River — Gold Medal — July
Post-runoff prime time. Caddis (size 14-16) heavy. PMDs (size 16-18) mid-morning. GREEN DRAKES (size 10-12) beginning — this is one of Colorado's premier Green Drake float fisheries. Big attractor dries taking large fish.
Conejos River — July
Caddis (size 14-16) heavy evenings. PMDs possible (size 16-18). BWOs on overcast days. Hoppers starting along meadow banks. Wild cutthroat respond to attractor dries in July. This is the prime month.
San Miguel River — July
PMDs (size 16-18) mid-morning. Caddis evenings. Hoppers starting along canyon banks. CO-145 corridor gives good access to mid-river sections. Stunning canyon scenery — pack a camera. Check lower water temps.
Lake Fork of the Gunnison — July
Caddis (size 14-16) evenings. PMDs possible (size 16-18). Hoppers starting along lake outlet meadow sections. Brown trout feeding actively. CO-149 pullouts provide good access. Flows dropping toward optimal.
August Hatch Calendar — Colorado Fly Fishing
South Platte River — August
PMDs continue (size 16-18). Tricos (size 20-24) early morning. Caddis evening. Terrestrials (ants #18-20, beetles, hoppers) productive mid-day. Hot summer fishing.
Arkansas River — August
PMDs dominant (size 16-18) hatching 9-11am. Caddis in evenings. Tricos possible. Terrestrials productive. Royal Gorge and Bighorn Canyon excellent.
Arkansas River — Pueblo Tailwater — August
Terrestrials productive (ants #18, beetles, small hoppers). Tricos (size 22-24) before 9am. PMDs tapering. City Park access makes this the most accessible summer fishery near Pueblo. Fish early.
Blue River — August
PMDs continue (size 16-18). Caddis evenings. Mysis imitations. Consistent flows make Blue River reliable when summer thunderstorms muddy other rivers. Fish may be selective and pressured.
Bear Creek — August
Terrestrials (ants #18-20, beetles, small hoppers #12-14) productive. Caddis evenings. Fish early morning before summer heat and weekend crowds.
Colorado River — August
GREEN DRAKES (size 10-12) at peak — one of the best dry fly hatches in all of Colorado. PMDs continue. Big fish rising to large flies. This is the month.
Frying Pan River — August
PMDs continue (size 16-18). Caddis evenings. Tricos (size 22-24) possible in slower flats sections. Terrestrials mid-day. The Pan's trophy rainbows surface feed heavily in August.
Roaring Fork River — August
PMDs continue (size 16-18). Caddis (size 14-16) evenings. Terrestrials (hoppers, ants, beetles) productive mid-day. Lower Fork near Glenwood has strong evening caddis action.
Cache la Poudre River — August
Caddis evenings (size 14-16). PMDs continue. Terrestrials (hoppers, ants, beetles) productive mid-day. Wild brown and rainbow trout respond well. Less crowded than South Platte options.
Taylor River — August
PMDs continue (size 16-18). Caddis in evenings. Tricos (size 22-24) possible in slower flats below Almont. Terrestrials mid-day. Prime summer fishing — book the Almont campsite early.
Gunnison River — August
Green Drakes possible mid-morning (size 10-12) — if you see large fish rising to big flies, this is why. PMDs continue. Caddis evenings. Gold Medal Gorge fishing at its absolute best.
Eagle River — August
PMDs continue. Caddis evenings (size 14-16). Terrestrials (ants, hoppers, beetles) productive mid-day. Eagle near Wolcott and Gypsum is significantly overlooked compared to the Vail stretch.
Yampa River — August
Caddis dominant evenings. PMDs continue. Terrestrials (hoppers, ants, beetles) productive mid-day. Yampa brown trout respond aggressively to hoppers. Outstanding summer option well off the beaten path.
Rio Grande — August
PMDs continue (size 16-18). Caddis evenings. Terrestrials (hoppers, ants, beetles) productive. Upper Gold Medal section near Creede and South Fork has excellent public access and very low pressure.
Crystal River — August
Caddis evenings (size 14-16). Yellow Sally possible early August. Terrestrials (hoppers, ants, beetles) productive mid-day. Small stream character requires stealth — fish spook easily in clear water.
Dolores River — August
PMDs continue. Caddis evenings. Terrestrials (hoppers, ants) mid-day. Lower flows post-peak irrigation make August–September excellent for wading. Red Canyon section particularly productive.
North Platte River — August
Caddis evenings. PMDs continue. Terrestrials (hoppers, ants, beetles) productive mid-day. North Park meadow stretch has undercut banks holding large browns. Virtually no pressure in August.
Slate River — August
Caddis evenings. Terrestrials (hoppers, ants, beetles) productive mid-day. Stealth essential in clear summer water. Brook trout respond well to small attractors. PMDs continue.
San Juan River — August
Green Drakes tapering. Caddis evenings. Terrestrials (hoppers, ants, beetles) productive mid-day. The San Juan through Pagosa sees surprisingly low pressure for such easy public access.
Animas River — August
Caddis dominant evenings. PMDs continue. Terrestrials (hoppers, ants, beetles) mid-day. Durango is a fly fishing destination town — the Animas through town offers convenient Gold Medal access.
East River — August
Green Drakes tapering. Caddis evenings. Terrestrials (hoppers, ants) productive mid-day. Wild cutthroat and rainbows in Gothic section are pristine — high-altitude fish in a stunning alpine setting.
Fraser River — August
PMDs continue. Caddis evenings. Terrestrials (hoppers, ants, beetles) productive mid-day. Tabernash and US-40 pullouts give roadside access to surprisingly underutilized fishing near Winter Park ski town.
Dream Stream — August
TERRESTRIALS PRIME — ants (#18-20), beetles, and hoppers along the meadow banks are effective for the largest fish. PMDs continue. Caddis evenings. August is when the biggest fish key on big flies. Wind almost always a factor.
Gore Creek — August
Green Drakes possible early August. PMDs continue (size 16-18). Terrestrials (hoppers, ants, beetles) mid-day. Vail summer crowds peak — arrive early or walk east toward Gore Creek Campground for less pressure and bigger fish.
Cheesman Canyon — August
PMDs continue. Terrestrials (hoppers, ants, beetles) on open canyon walls. Caddis evenings. Crystal-clear water means full stealth approach — watch your shadow at all times.
Williams Fork River — August
PMDs continue. Caddis evenings. Terrestrials (hoppers, ants) productive. Consistent tailwater flows year-round. One of Grand County's genuinely overlooked summer fisheries.
Colorado River — Gold Medal — August
GREEN DRAKES (size 10-12) at peak or tapering. PMDs continue. HOPPERS (size 8-12) productive from the boat along grassy banks — some of the best hopper-dropper float fishing in the state. Caddis evenings.
Conejos River — August
Hoppers (size 8-12) productive along the banks — Conejos has excellent meadow sections for hopper fishing. Caddis evenings. Wild cutthroat taking attractor dries. Best month for the upper Platoro sections.
San Miguel River — August
Hoppers productive (size 8-12) mid-day in canyon sections. Caddis evenings. PMDs continue. WARNING: check water temperature in lower Naturita canyon — can warm above 68°F in August. Fish early morning.
Lake Fork of the Gunnison — August
BEST MONTH — flows at seasonal low, big brown trout feeding aggressively ahead of spawn. Hoppers (size 8-12) productive along stream banks. Caddis evenings. Lake Fork in August: trophy browns in remote canyon country.
September Hatch Calendar — Colorado Fly Fishing
South Platte River — September
BWOs return strong on cloudy days (size 18-20) — best dry fly month of the year on the Platte. PMDs tapering. Streamer fishing productive.
Arkansas River — September
PMDs tapering. BWOs returning on cloudy days (size 18-20). Caddis possible. Excellent fall fishing — this is one of Colorado's best fall rivers.
Arkansas River — Pueblo Tailwater — September
BWOs returning on overcast days (size 18-20). Terrestrials continue. Cooler temps improve afternoon fishing. September is a transition month — strong early mornings, good evenings.
Blue River — September
BWOs returning (size 18-20). PMDs tapering. Midges picking up. Mysis year-round. Fall fishing excellent — consistent tailwater flows, less pressure after Labor Day crowds thin out.
Bear Creek — September
BWOs returning (size 18-20). Caddis possible. Fall is a hidden gem — less pressure, active fish, cooling water. Denver anglers overlook this.
Colorado River — September
Green Drakes tapering. BWOs returning on cloudy days (size 18-20). PMDs possible. Fall streamer fishing for aggressive large trout.
Frying Pan River — September
BWOs returning strong on overcast days (size 18-20) — the best dry fly month on the Pan. PMDs tapering. Cool air triggers excellent hatches. This is prime Frying Pan season.
Roaring Fork River — September
BWOs returning (size 18-20). PMDs tapering. Caddis possible. Excellent fall fishing — less pressure, active fish, cooling water. Fork brown trout are large in September.
Cache la Poudre River — September
BWOs returning (size 18-20). Caddis possible. Excellent fall fishing — the canyon below Ted's Place has easy access and less pressure than Front Range competition.
Taylor River — September
BWOs returning strong on overcast days (size 18-20). PMDs tapering. Midges year-round. Outstanding fall fishing — tailwater stability, cool evenings, fish feeding aggressively.
Gunnison River — September
BWOs returning (size 18-20). Green Drakes tapering. PMDs possible. Fall fishing on the Gunnison Gorge is world-class — trophy fish, remote canyon, turning aspen above the rim.
Eagle River — September
BWOs returning (size 18-20). PMDs tapering. Caddis possible. Good fall fishing — Eagle brown trout become aggressive. Less pressure than September on the South Platte.
Yampa River — September
BWOs returning (size 18-20). Caddis possible. September on the Yampa is the best-kept secret in Colorado fly fishing — large browns, zero pressure, fall colors, bugling elk.
Rio Grande — September
BWOs returning strong (size 18-20). PMDs tapering. Caddis possible. September on the Rio Grande is outstanding — cool nights, active fish, striking fall colors, minimal crowds.
Crystal River — September
BWOs returning (size 18-20). Caddis possible. Fall fishing is a hidden gem — light pressure, wild trout, beautiful Crystal Valley scenery below Marble. One of Colorado's most scenic autumn options.
Dolores River — September
BWOs returning (size 18-20). PMDs tapering. Midges picking up. Fall fishing excellent — Dolores tailwater is significantly less crowded than northern Colorado rivers in September.
North Platte River — September
BWOs returning (size 18-20). Caddis possible. September on the North Platte is peak season — large wild browns active, fall colors, elk bugling in North Park. This is the best month to make the Walden drive.
Slate River — September
BWOs returning (size 18-20). Caddis possible. Fall on the Slate is beautiful — minimal pressure, active fish, aspen gold. North of CB on Slate River Road is the go-to access.
San Juan River — September
BWOs returning (size 18-20). Caddis possible. Excellent fall fishing — Pagosa Springs in September is mild, the river is clear, and browns are active. One of Southwest Colorado's best fall options.
Animas River — September
BWOs returning (size 18-20). Caddis possible. September fall fishing excellent — browns pre-spawn active, clear water, cooling temps. The Gold Medal stretch earns its designation in September.
East River — September
BWOs returning (size 18-20). Caddis possible. Fall on the East River is exceptional — Crested Butte aspen colors, wild cutthroat, light pressure. This is the hidden gem month.
Fraser River — September
BWOs returning (size 18-20). PMDs tapering. Excellent fall fishing — Grand County aspen color, minimal pressure, wild browns active. Fraser in September is a quality option for an I-70 corridor trip.
Dream Stream — September
BWOs returning strongly (size 18-20). FALL SPAWNING RUN STARTING — the biggest brown trout of the year begin moving into this reach September through October. Fish can exceed 24". Treat them with care.
Gore Creek — September
BWOs returning (size 18-20). PMDs tapering. Caddis possible. Resort crowds thin dramatically after Labor Day — September Gore Creek is the reward for the summer wait. Excellent fall fishing.
Cheesman Canyon — September
BWOs returning strongly (size 18-20). BEST MONTH — cool canyon temps, clear water, active fish, minimal pressure. September on Cheesman Canyon is the reward for the effort. Plan the full day.
Williams Fork River — September
BWOs returning (size 18-20). PMDs tapering. Midges picking up. Fall on the Williams Fork near Parshall — quality browns, empty canyon, Grand County fall colors. The secret stays secret in September.
Colorado River — Gold Medal — September
BWOs returning (size 18-20). Hoppers continue. Streamer fishing picking up as big browns get aggressive pre-spawn. Classic fall float: Pumphouse to State Bridge in early September morning light.
Conejos River — September
BWOs returning (size 18-20). Hoppers continue. Fall on the Conejos: wild cutthroat feeding aggressively, aspens turning in the Rio Grande National Forest. One of Colorado's most beautiful fall fisheries.
San Miguel River — September
BWOs returning (size 18-20). Hoppers continue early September. Excellent fall fishing — remote canyon with fall colors. Less pressure than any week in summer. San Miguel in September is a secret worth keeping.
Lake Fork of the Gunnison — September
BWOs returning (size 18-20). Hoppers continue. FALL PRIME — trophy browns on the move pre-spawn. September on the Lake Fork near Lake City is outstanding and underutilized. Aspens turning on the CO-149 drive.
October Hatch Calendar — Colorado Fly Fishing
South Platte River — October
Best BWO month — heavy hatches on overcast days (size 18-20). Midges picking up. Streamer fishing for aggressive pre-winter fish.
Arkansas River — October
Best BWO month (size 18-20). Midges picking up. Streamer fishing productive. Royal Gorge corridor excellent in October.
Arkansas River — Pueblo Tailwater — October
BWOs peak (size 18-20). Midges picking up. Streamer fishing for trophy rainbows in deep runs. Pueblo tailwater in October with less pressure — one of the best times to fish it.
Blue River — October
Best BWO month (size 18-20). Midges dominant. Flows consistent. Mysis imitations throughout. October on the Blue is underrated — fewer crowds than South Platte, same quality fish.
Bear Creek — October
BWOs on overcast days (size 18-20). Midges picking up. CDOW stocks heavily — stockers respond to egg patterns and bright attractor flies.
Colorado River — October
BWOs strong on overcast days (size 18-20). Midges picking up. Streamer fishing for large fish before winter. Remote and uncrowded.
Frying Pan River — October
BWOs at peak (size 18-20). Midges picking up. Streamer fishing for aggressive large rainbows and browns. One of the most beautiful fall fisheries in Colorado. Fewer crowds after Labor Day.
Roaring Fork River — October
BWOs peak on overcast days (size 18-20). Midges picking up. Streamers for large fish. The Roaring Fork in October is an underrated fall gem — one of Colorado's best.
Cache la Poudre River — October
BWOs strong on overcast days (size 18-20). Midges picking up. Brown trout pre-spawn activity excellent. Poudre Canyon fall foliage is outstanding — worth the drive from Fort Collins.
Taylor River — October
BWOs at peak (size 18-20). Midges dominant. Streamer fishing for aggressive fish before winter. Taylor in October is exceptional — fewer people, exceptional fish activity.
Gunnison River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for large trophy fish. Gunnison Gorge in October requires physical fitness — 4 trail options, all steep. Rewards exceptional.
Eagle River — October
BWOs strong on overcast days (size 18-20). Midges picking up. Streamers for large pre-spawn browns. Eagle River fall fishing is the most underutilized angling in the I-70 corridor.
Yampa River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for large pre-spawn browns. Craig and the lower Yampa Canyon fishing well in October. 4WD recommended for some access points.
Rio Grande — October
BWOs peak (size 18-20). Midges picking up. Streamer fishing for pre-winter fish. Rio Grande is remote enough that October sees minimal pressure and very aggressive fish.
Crystal River — October
BWOs on overcast days (size 18-20). Midges picking up. Streamer fishing for larger fish. Crystal River in October sees almost no angling pressure — explore the canyon.
Dolores River — October
BWOs peak (size 18-20). Midges dominant. Streamer fishing for aggressive browns. Southwest Colorado October fishing is an underrated and beautiful experience.
North Platte River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for large pre-spawn browns. Northgate Canyon in October with zero pressure and trophy-class fish. AWD required for canyon access road.
Slate River — October
BWOs on overcast days (size 18-20). Midges picking up. Streamer fishing possible for larger fish. October on the Slate is late season — prepare for early snow in Crested Butte.
San Juan River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for pre-spawn browns. West Fork and above Pagosa are remote and beautiful in October fall colors.
Animas River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for large pre-spawn browns in the Gold Medal section. Purple Cliffs downstream boundary — explore below for less pressure.
East River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for larger browns in lower East River near Almont. Gothic road closing with snow — move to lower sections in October.
Fraser River — October
BWOs strong on overcast days (size 18-20). Midges picking up. Streamer fishing for pre-spawn browns. Fraser Valley winter comes early — October is often the last good month before conditions deteriorate.
Dream Stream — October
BWOs peak (size 18-20). FALL SPAWNING PEAK — 20"+ brown trout on the move through the meadow. Egg patterns (San Juan Worm, Sucker Spawn size 14-16) deadly for staging spawners alongside BWO dries. Best month for trophy fish.
Gore Creek — October
BWOs peak (size 18-20). Midges increasing. Streamer fishing for pre-spawn browns. Gore Creek brown trout can be surprisingly large. East Vail access points in October are outstanding.
Cheesman Canyon — October
BWOs peak (size 18-20). Midges increasing. Streamer fishing for pre-spawn browns in deeper pools. Early snow possible on the Gill Trail — check conditions and bring traction devices.
Williams Fork River — October
BWOs strong (size 18-20). Midges dominant. Streamer fishing for pre-spawn browns. Williams Fork in October with peak fall colors and zero crowds. Underrated doesn't begin to cover it.
Colorado River — Gold Medal — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing at peak — large articulated streamers for the biggest browns of the year. Fall float fishing on this river is underappreciated.
Conejos River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for brown trout pre-spawn. October Conejos in full fall color — worth the drive. Wild cutthroat still active. Platoro road condition check required.
San Miguel River — October
BWOs strong (size 18-20). Midges picking up. Streamer fishing for pre-spawn browns in canyon sections. October on the San Miguel in full canyon color — one of the most beautiful fall rivers in Colorado.
Lake Fork of the Gunnison — October
BWOs peak (size 18-20). Midges increasing. Streamer fishing for spawning brown trout. October Lake Fork: 20"+ browns possible, remote canyon, zero pressure. Worth the drive from anywhere in Colorado.
November Hatch Calendar — Colorado Fly Fishing
South Platte River — November
BWOs on warm/cloudy afternoons (size 20-22). Midges dominant. Streamers for big fish. Water cooling and clearing fast.
Arkansas River — November
BWOs on overcast afternoons. Midges dominant. Streamer fishing for large browns. Flows stable and clear.
Arkansas River — Pueblo Tailwater — November
Midges dominant (size 20-26). BWOs on mild afternoons. Streamer fishing. Reservoir regulation keeps flows stable. Pueblo's mild climate means November is comfortable fishing.
Blue River — November
Midges primary. BWOs on cloudy afternoons. Mysis shrimp year-round. Reservoir regulation maintains fishable conditions through late fall. One of the last rivers to become difficult.
Bear Creek — November
Midges primary. BWOs possible on mild afternoons. Stream slowing for winter. Small stream winter fishing for the dedicated.
Colorado River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing. Big remote river — fewer crowds, serious fish.
Frying Pan River — November
Midges dominant (size 20-26). BWOs on cloudy afternoons. Streamer fishing productive. Reservoir regulation keeps flows consistent through late fall. The Pan never really stops fishing.
Roaring Fork River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for large pre-spawn browns. Flows dropping and clearing. Upper Fork near Aspen cooling fast.
Cache la Poudre River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for large browns. Canyon narrows above Poudre Park are beautiful in November. Light pressure.
Taylor River — November
Midges (size 22-28) primary. BWOs on cloudy afternoons. Reservoir regulation keeps flows consistent through late fall. The Taylor in November is an underrated gem for serious anglers.
Gunnison River — November
Midges dominant. BWOs on overcast afternoons. Streamers for large fish. Black Canyon section requires technical scrambling — plan carefully, check trail conditions.
Eagle River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for spawning browns. Flows dropping and clearing post-fall. Gypsum section most reliable November access.
Yampa River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing. Steamboat Springs section accessible year-round through town. Yampa winding down for the season.
Rio Grande — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for large browns. Upper valley cools fast — check road conditions for Creede and South Fork access as snow arrives.
Crystal River — November
Midges primary. BWOs on mild afternoons. Small stream winter fishing for the dedicated. Crystal Valley scenery spectacular in fall. Upper sections begin icing over.
Dolores River — November
Midges primary. BWOs on mild afternoons. Tailwater stays fishable. Cortez/Dolores area has milder late-fall weather than mountain towns. Good option when high country is locked up.
North Platte River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing. North Park roads becoming treacherous — check conditions before driving to Walden. Season ending fast.
Slate River — November
Midges primary. Slate River Road may become impassable with early snow. Small stream fishing for the dedicated — beautiful but demanding. Season essentially over by late November.
San Juan River — November
Midges dominant. BWOs on mild afternoons. Pagosa Springs clinic climate makes late-season fishing comfortable. Riverwalk stretch accessible through November.
Animas River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for spawning browns. Durango's mild climate extends the season comfortably through November.
East River — November
Midges primary. BWOs on mild afternoons. Gothic section inaccessible. Almont and CB South area most accessible late-season. Season wrapping up fast as Crested Butte enters ski season.
Fraser River — November
Midges dominant. BWOs on mild afternoons. Flows dropping post-season. Grand County weather deteriorating — check road conditions and dress for mountain cold before heading to Winter Park.
Dream Stream — November
Midges (size 22-26) dominant. BWOs on mild afternoons. Post-spawn browns feeding aggressively. Fewer crowds than summer — November Dream Stream is one of Colorado's great secrets. Cold but worth it.
Gore Creek — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for browns. Vail shifts into ski season mode — Gore Creek fishes quietly while the mountain gets the attention.
Cheesman Canyon — November
Midges dominant. BWOs on mild afternoons. Late-season canyon fishing. Shorter days mean faster hike-out — plan accordingly. Trail conditions deteriorating with early snow.
Williams Fork River — November
Midges primary. BWOs on mild afternoons. Reservoir regulation keeps flows consistent. Cold and remote Grand County conditions. Worth every mile for serious winter fishing.
Colorado River — Gold Medal — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for post-spawn browns. Flows dropping and clearing. River returning to wade-friendly levels at Pumphouse access.
Conejos River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing. Upper Conejos and Platoro area may have early snow and road closures by November. Lower CO-17 sections accessible later into the season.
San Miguel River — November
Midges dominant. BWOs on mild afternoons. Streamer fishing. Mountain road conditions deteriorating — check before driving upper CO-145 and CO-62 sections. Lower canyon near Naturita accessible.
Lake Fork of the Gunnison — November
Midges dominant. BWOs on mild afternoons. Streamer fishing for post-spawn browns feeding aggressively. CO-149 accessible but check weather — Lake City area can have early snow in November.
December Hatch Calendar — Colorado Fly Fishing
South Platte River — December
Midges (size 22-26) are primary. Occasional BWO on mild days. Streamers for large fish in deep runs. Cold and clear.
Arkansas River — December
Midges (size 22-26) primary. BWOs on mild days. Streamers. Fish slow-moving deep runs.
Arkansas River — Pueblo Tailwater — December
Midges (size 20-26) primary. Consistent tailwater flows. Pueblo's lower elevation (4,700 ft) means warmer air temps than mountain rivers. Year-round tailwater at its most accessible.
Blue River — December
Midges (size 22-26) year-round dominant. Mysis imitations essential — size 16-20 white/cream, fished on a long leader. Flows remain consistent through winter. Cold but reliably fishable.
Bear Creek — December
Midges (size 22-24) primary. Low flows typical — below 15 CFS is tough. Fish deep pools and slow runs with nymph rigs.
Colorado River — December
Midges (size 20-24) primary. Streamers for large fish in deep runs. Cold and remote. Dress for mountain winter conditions.
Frying Pan River — December
Midges (size 20-26) primary. Consistent tailwater flows year-round. Large fish active in cold water. Cold canyon conditions — dress warmly and watch for ice in rod guides.
Roaring Fork River — December
Midges (size 20-24) primary. Streamers in deep runs. Lower section near Glenwood most accessible in winter. Cold canyon — Basalt section fishable with proper preparation.
Cache la Poudre River — December
Midges (size 22-26) primary. Fish accessible lower canyon sections. Cold conditions — Poudre Canyon Hwy can be icy. Check CDOT road conditions before driving.
Taylor River — December
Midges (size 22-28) year-round. Tailwater maintains fishable temps and flows through December. Cold mountain valley — dress for it. World-class winter tailwater fishing.
Gunnison River — December
Midges (size 20-24) primary. Streamers in deep runs. Cold and remote — this is for dedicated anglers. Gorge trail access can be treacherous with snow and ice.
Eagle River — December
Midges (size 22-26) primary. Cold I-70 corridor conditions. Fish deep pools in Gypsum section. Light pressure December through February — the Eagle to yourself.
Yampa River — December
Midges (size 20-24) primary. Cold Northwest Colorado conditions — temperatures can drop sharply. Fish deep runs near Steamboat Springs. Dress for Routt County winter.
Rio Grande — December
Midges (size 20-24) primary. Cold San Luis Valley conditions — frigid nights common. The long drive from Denver requires a commitment. Check flows and weather before going.
Crystal River — December
Midges (size 22-24) primary. Small stream, cold conditions. Fish accessible lower sections near Carbondale only. Road access above Redstone becomes limited with winter snowfall.
Dolores River — December
Midges (size 20-24) year-round below McPhee. Consistent tailwater flows through December. Southwest Colorado location means more fishable winter days than higher-elevation rivers.
North Platte River — December
Midges (size 22-26) when accessible. North Park in winter is extreme — temperatures well below zero. Limited winter access near Walden only. This river rewards the dedicated and well-prepared.
Slate River — December
Midges (size 22-24) primary when accessible. Crested Butte ski season means snow on Slate River Road. Very limited access December through February. Fish the town stretch only.
San Juan River — December
Midges (size 20-24) primary. Pagosa Springs mild winters mean the San Juan stays fishable when northern rivers freeze. Riverwalk access year-round.
Animas River — December
Midges (size 20-24) primary. Gold Medal section accessible year-round through Durango. Mild Southwest Colorado winter makes December fishing viable when northern rivers are frozen.
East River — December
Midges (size 22-24) primary when accessible. Crested Butte in full ski season — limited fishing access except near Almont. East River essentially closed for the winter season.
Fraser River — December
Midges (size 22-26) primary. Grand County deep winter. Moffat Tunnel diversion at peak winter operation. Cold and remote — limited December access. The Fraser is a summer and fall river.
Dream Stream — December
Midges (size 22-26) primary. South Park in December is serious mountain cold — temperatures well below zero overnight. Fish the warmest part of the afternoon. Big browns active. You'll have it to yourself.
Gore Creek — December
Midges (size 22-26) primary. Cold mountain valley. Paved rec path cleared for ski season gives year-round access. Fish accessible urban section through Vail village.
Cheesman Canyon — December
Midges (size 22-26) when accessible. Gill Trail may have snow and ice — microspikes recommended. Winter Cheesman Canyon requires careful planning and full cold-weather gear. Worth it for the solitude.
Williams Fork River — December
Midges (size 22-26) year-round below reservoir. Consistent flows through December. Williams Fork in winter: solitude guaranteed, quality fish, and a reminder that the best Colorado tailwaters aren't always the famous ones.
Colorado River — Gold Medal — December
Midges (size 20-24) primary. Streamers in deep holes and eddies. Cold canyon conditions. Some of the best winter streamer fishing in Grand County — BLM land keeps this accessible year-round.
Conejos River — December
Midges (size 22-26) primary. Cold San Luis Valley winters — dress accordingly. Conejos River accessible near Mogote in December for the most dedicated. Wild cutthroat worth protecting year-round.
San Miguel River — December
Midges (size 22-26) primary. Upper Telluride sections closed by winter. Lower canyon near Naturita accessible but cold. San Miguel in December for the committed — remote, cold, beautiful, empty.
Lake Fork of the Gunnison — December
Midges (size 22-26) primary. Cold remote conditions. Lake Fork accessible near Gateview only in December. Trophy browns resting post-spawn — handle carefully. The most remote December fishing in Colorado.
How to Use This Calendar
Match the Hatch
Hatches listed are what you're likely to encounter, not guarantees. Weather and water temperature drive emergence. Overcast days trigger BWO and PMD hatches — sunny days slow them down.
Check Conditions First
Hatch timing means nothing if the river is blown out from runoff. Always check the live gauge data on each river's page before making the drive. Conditions change daily in spring.
Ask the Hatch Advisor
For real-time recommendations based on current CFS, temperature, and today's conditions — use the AI Hatch Advisor on any river detail page. It knows what the gauge is showing right now.
Go deep on a river