Colorado River Guide: Fly Fishing and Floating

Quick Reference

What	When	Key Numbers
Arkansas River	Aug 15 - Oct (after rafting flows drop)	225-300 CFS ideal wade fishing
South Platte (Cheesman/Deckers)	Year-round	150-400 CFS ideal; 6X-7X tippet
Upper Colorado float	July - September	1,500-3,300 CFS ideal
Fryingpan River	Year-round (Green Drakes July-Sept)	80-150 CFS ideal
Roaring Fork	Late June - October (Green Drakes late June)	700-2,500 CFS ideal float

Overview

Colorado offers some of the finest trout fishing and river floating in the American West. Fed by snowmelt from the Continental Divide, the state's rivers range from technical tailwaters with trophy fish to big-water wilderness runs. Nearly 325 miles of water carry the Gold Medal designation, meaning they hold at least 60 pounds of trout per acre with significant numbers of fish over 14 inches.

For anglers, Colorado delivers year-round fishing on tailwaters and seasonal opportunities on freestone streams. For floaters, the Arkansas River alone draws more commercial rafters than almost any river in the country, while quieter stretches of the Colorado and Yampa offer multi-day wilderness experiences.

Seasons and Runoff

Colorado rivers follow a predictable annual pattern driven by snowpack:

Season	Timing	Conditions	Best Bet
Winter	Dec-Mar	Tailwaters fish well, midge hatches daily, uncrowded	Fryingpan, South Platte, Blue
Spring	Apr-May	Runoff begins, freestones go off-color	Tailwaters only
Runoff	May-Jun	Peak flows, dangerous on freestones	Arkansas rafting, tailwaters for fishing
Summer	Jul-Aug	Rivers clear, prolific hatches, prime floating	Everything fishable
Fall	Sep-Oct	Best fishing, stable flows, browns aggressive	Freestones and tailwaters

Key timing notes:

• August 15th is when augmented rafting flows end on the Arkansas, dropping from 1,500+ CFS to under 400 CFS - wade fishing improves dramatically
• Green Drake hatches start mid-June on the Roaring Fork and Fryingpan
• Fall BWO hatches run through October on most rivers
• High country streams above 9,000 feet may not clear until late July

Major River Systems

Arkansas River

The Arkansas drops over 5,000 feet in its first 125 miles through Colorado. Over 102 miles from Leadville to above Royal Gorge carry Gold Medal status - one of the longest Gold Medal stretches in the state.

Flow Windows:

CFS	Conditions
225-300	Ideal wade fishing - can cross to less-pressured side
300-600	Good fishing, some wading limitations
600-1,500	Float fishing preferred, commercial rafting season
1,500+	High water rafting, fishing tough

For anglers: Browns and rainbows throughout. The stretch near Salida is particularly productive. After August 15th when rafting flows drop, the river becomes very wadeable at 275 CFS with excellent clarity and water temps in the upper 40s to low 50s.

Key flies: Caddis (sizes 14-18), Yellow Sallies (sizes 14-16), Stoneflies (sizes 8-12), Pheasant Tails and Hare's Ears for nymphing

For floaters:

• Browns Canyon (Ruby Mountain to Hecla Junction): 8 miles of Class III rapids through National Monument. Put in at Ruby Mountain Campground (can back trailers to boat ramp) or Fisherman's Bridge (4.5 miles south of Buena Vista on US 285, turn left on CR 301). Take out at Hecla Junction above Salida.
• Royal Gorge: Class IV-V between 1,000-foot canyon walls. Commercial trips only for inexperienced paddlers.

Parking: Ruby Mountain and Hecla Junction require a CPW parks pass (daily or annual). Browns Canyon National Monument itself has no entrance fee.

Check Arkansas River at Salida for current flows.

South Platte River

The most accessible major trout river from Denver. Cheesman Canyon and Deckers are legendary technical fisheries - expect educated trout, long leaders, and small flies.

Flow Windows (Deckers/Cheesman):

CFS	Conditions
80-150	Very technical, experienced anglers
150-400	Ideal range - good wading, active fish
400-600	Higher but fishable
600+	Difficult wading, reduced visibility

Key Sections:

Dream Stream (3.8 miles below Spinney Reservoir to Elevenmile Reservoir)

• Open banks, trophy fish on spawning runs spring and fall
• Easier wading than canyon sections
• Less pressure than Cheesman/Deckers

Cheesman Canyon (below Cheesman Dam)

• Gold Medal, catch-and-release only, flies and lures only
• Crystal-clear water, granite boulders, large rainbows (3,000+ trout per mile)
• Access: Hike-in only via Gill Trail. Trailhead at 23785 CR 126, Pine, CO - parking lot holds ~20 cars, fills early on weekends. 5.5-mile out-and-back trail with steep sections. No overnight parking. Bring hiking boots - loose gravel. Watch for poison ivy along riverbanks.
• Allow 45 minutes to hike in

Deckers (below Cheesman Canyon)

• More accessible, but heavily pressured
• Ample parking along Hwy 67 and behind Flies and Lies fly shop
• Parking lot behind Flies and Lies gives access up or down river
• Pike National Forest land - may require USFS day-use pass
• Warning: Parking fills by 8am on summer weekends

Key flies: This is small-fly water. Zebra Midges (18-24), RS2 (18-24), Mercury Midges, Juju Baetis (20-24), Trico patterns (20-24). PMDs (16-20) in summer. Griffith's Gnat for midge clusters.

Tip: South Platte trout are notoriously selective. Go lighter on tippet than you think (6X-7X), fish drag-free, and approach slowly. Flow changes from Cheesman Dam releases can affect fishing quickly - check conditions before you go.

Colorado River

Running from its headwaters near Granby through Glenwood Canyon, the Colorado offers excellent fishing and floating across distinct sections.

Upper Colorado (Kremmling to State Bridge): The classic summer float. See our Upper Colorado summer guide for detailed flow windows and access.

CFS	Conditions
Under 800	Low - possible scraping
800-1,500	Relaxed float, some shallow spots
1,500-3,300	Ideal - good current, Class II rapids run clean
3,300-5,500	Faster, more technical
Over 5,500	High water - bridge clearance issues at second bridge

Put-in: Pumphouse Recreation Site (BLM campground with boat ramp) Take-out: State Bridge (14 miles, 4-6 hours depending on flow)

Key hazard: Yarmony (Hoyt) Rapid becomes a legit Class III at 2,500+ CFS with a boulder creating a hole that can flip rafts.

Gore Canyon: Expert-only whitewater, Class V+. Commercially run by Dvorak Expeditions with portages at Gore Rapid and Tunnel Falls. Not for casual floaters - Kirshbaum Rapid at the end is too long to portage.

Glenwood Canyon: Scenic canyon with good access along I-70. Mix of pocket water and runs. Good fishing access at rest areas.

Fryingpan River

One of Colorado's finest tailwaters. The 14 miles below Ruedi Dam is Gold Medal water with year-round fishing and some of the most prolific hatches in the state.

Flow Windows:

CFS	Conditions
60-85	Winter flows, very technical
80-150	Ideal - optimal clarity and wading
150-200	Still good, manageable current
200+	Can muddy, difficult wading

Hatches (this is a hatch-driven fishery):

• Green Drakes (July-September): Sizes 10-14. The signature hatch. Fish Sparkledun Green Drakes, Green Drake Cripples, or CDC Thorax patterns.
• PMDs (June-August): Sizes 14-18
• BWOs (Spring and Fall): Sizes 18-22
• Midges: Year-round, sizes 18-24. Zebra Midges, Mercury Midges
• Mysis Shrimp: Year-round near the dam, sizes 16-20. Tim's Mysis, Craven's Mysis, Will's Epoxy Mysis

Key insight: The upper mile below the dam ("Toilet Bowl" area) has the biggest fish due to Mysis shrimp from the reservoir - but also the heaviest pressure. Miles 2-6 offer better solitude with a mix of riffles and deep slots.

Character: This is a presentation fishery, not match-the-hatch. Keep flies drag-free, use fine tippet (5X-6X), and fish from the bank when possible. Trout are well-fed and refuse sloppy drifts.

Access: 8.5 miles of public land and easements. Good pullouts along Fryingpan Road (CR 104) from Basalt.

Gunnison River

The Gunnison flows through Black Canyon National Park and Gunnison Gorge National Conservation Area - one of the most spectacular and remote fisheries in Colorado.

Flow Windows:

CFS	Conditions
300-450	Low water - excellent wading, hard to float
400-600	Ideal fishing - wade or float
600-800	Good drift boat water
800+	Easy drift boat, wade fishing limited

Black Canyon Section:

• Demanding hike down from the rim (3+ hours each way)
• True wilderness fishing with trophy rainbow potential (20+ inches)
• Sudden flow changes possible from dam releases
• Worth the effort for solitude and big fish

Gunnison Gorge (below Black Canyon):

• 14 miles of Class II-III water
• Permits required for floating
• Access via 4-mile hike from Chukar Trail or float from upstream put-in
• Less pressure than more accessible rivers
• Stonefly and caddis hatches drive the fishing

Key flies: Golden Stones (8-12), Caddis (14-18), Pheasant Tails, Pat's Rubber Legs

Roaring Fork River

Gold Medal water for 22 miles from Basalt to the confluence with the Colorado at Glenwood Springs. A productive freestone with good public access.

Flow Windows:

CFS	Conditions
200-350	Excellent wading, lower river may be too low to float
700-2,500	Ideal drift boat range
2,500-5,000	High but floatable for experienced rowers
5,000+	Runoff conditions - wait it out
13,000+	Peak runoff on big snow years - unfishable for weeks

Sections:

Upper (Aspen area): Smaller water, higher gradient, pocket water fishing

Middle (Basalt to Carbondale): 13 miles of Gold Medal water. Popular with float fishermen early season but usually too low to float by late July. Excellent wade fishing at 200-350 CFS. Healthy trout populations, less boat traffic than lower river.

Lower (Carbondale to Glenwood): Bigger water, joins the Fryingpan at Basalt which adds cold, clear flow

Hatches:

• Green Drakes (late June-July): The famous hatch - anglers travel from across the country for this. Sizes 10-14.
• Caddis, Stoneflies, PMDs through summer
• BWOs in fall

Key flies: Green Drake dries and emergers (10-14), Elk Hair Caddis (14-18), Stimulators (10-14), Pheasant Tails, copper johns

Access: Good public access in Basalt and Carbondale. Several fishing access sites along Highway 82.

Blue River

A tailwater fishery below Dillon Reservoir and Green Mountain Reservoir, offering accessible fishing close to Summit County ski towns.

Flow Windows:

CFS	Conditions
50-100	Typical winter flows - very technical
100-200	Good fishing, manageable
200-400	Higher flows, nymphing productive
1,600+	High water - difficult fishing

Below Dillon (Silverthorne):

• Trophy potential - some of the largest trout in Summit County
• Very cold water (34-38°F) from bottom releases
• Fish concentrate in slower runs and deeper pools
• Best fishing window: 10am-2pm when temps align for feeding
• This is NOT a morning fishery due to cold water
• Year-round fishing but technical conditions

Below Green Mountain:

• More water, consistent fishing
• Less pressure than Silverthorne section

Key flies: Small flies are essential. Mysis Shrimp (18-22), Zebra Midges (20-24), Scuds (16-18), RS2s, Juju Midges. This is 6X-7X tippet water.

Access: Walk-and-wade from downtown Silverthorne. Parking along Blue River Parkway. The town section is family-friendly and less intimidating than canyon sections of other rivers.

Tip: Check flows before driving - Denver Water controls releases and levels can fluctuate significantly day to day.

Animas River

Running through Durango, the Animas provides urban fishing access and some of the state's most challenging whitewater.

Flow Windows (Durango section):

CFS	Conditions
150-300	Ideal wading - high clarity, good visibility
300-800	Fishable but wading limited
800-2,000	Float fishing, rafting
4,600+	High summer flows - rafting/kayaking, tough fishing

Fishing:

• Gold Medal section through downtown Durango (Lightner Creek to Rivera Crossing)
• Big water - nearly 100 feet wide with huge rocks and deep holes
• Browns and rainbows to 20+ inches
• Year-round access - never freezes or gets slushy
• Best times: Fall through early spring (avoid late April-May runoff)

Key flies: Stoneflies (8-12), Caddis (14-18), Hoppers in summer (8-12), Streamers for big browns

Whitewater:

• Upper Animas (above Silverton): Class IV-V, among the most difficult commercially rafted water in the country. Cold water, continuous rapids, remote. Expert only or guided trips.

Access: Easy access from downtown Durango. Several parks and access points along the river.

Note: The Animas has experienced mine-related water quality issues in the past. Check current conditions before planning a trip.

Rio Grande

South Fork boasts the longest stretch of Gold Medal water in Colorado - nearly 20 miles of the Rio Grande carrying the designation.

Flow Windows:

Location	Low	Normal	High
Thirty Mile	85	400-700	967
Wagon Wheel Gap	261	800-1,200	1,950
Del Norte	350	1,000-1,500	2,450

Below 600 CFS: Float trips take ~3 hours, very wadeable Above 1,500 CFS: Higher flows, faster floating

Character: The river gets bigger between South Fork and Del Norte. Limited public access between the two towns makes float fishing popular for the lower stretch.

Hatches:

• Salmonfly Hatch (mid-June): The signature event. You can follow the hatch upriver through July.
• Stoneflies, Caddis through summer
• Terrestrials (hoppers, beetles) July-September

Key flies: Salmonfly patterns (4-8), Sofa Pillow, Bird's Stone, large Stimulators, Hoppers (8-12), Dropper rigs with stonefly dries

Sections:

• South Fork to Del Norte: Gold Medal water, big browns and rainbows. Fish hold in deeper water near banks and under willow roots.
• Box Canyon: More remote, requires hiking

Access: Consider hiring a local guide for the float section - limited bank access between South Fork and Del Norte.

Williams Fork River

A lesser-known tailwater that fishes well when flows are right. Remote location means less pressure than other Front Range tailwaters.

Flow Windows:

CFS	Conditions
15-50	Very low but fishable
50-100	Winter flows
100-250	Ideal - entices fish from Colorado River
250-300	Still good
300+	Higher water

Character: The Williams Fork fishes best when flows are high enough to draw fish up from the Colorado River (100-200+ CFS). When this happens, fishing can be excellent with less competition.

Hatches: Midges, Baetis, Caddis. Summer brings mayflies, caddis, terrestrials, and small stoneflies - dry fly fishing can be exceptional.

Key flies: RS2 (18-22), Zebra Midges, Pheasant Tails, small Perdigons. Streamers productive.

Access: Two access points, both requiring ~20 minute hikes:

1. Off Hwy 40 at Parshall - cross the Colorado River
2. County Road 3 - DOW parking area ~1/3 mile south of Colorado River

Note: Denver Water Board controls flows from the dam - levels can change day to day. Check before driving.

Best seasons: Summer and fall most productive. Fishable year-round.

Beginner-Friendly Options

If you're new to Colorado rivers:

For floating:

• Upper Colorado (Pumphouse to State Bridge): Class I-II, wide river, forgiving. Prime July-August.
• Arkansas River (Bighorn Sheep Canyon): Scenic Class II-III rafting. Multiple outfitters, family-friendly.

For fishing:

• Blue River in Silverthorne: Walk-and-wade from town, smaller water, less intimidating than canyons
• Arkansas near Salida (after Aug 15): Wadeable flows, good access, less technical than tailwaters
• San Juan River (below Navajo Dam, NM): Technically New Mexico but accessible from Durango. Legendary tailwater with consistent fishing and easier wading than most Colorado options

Technical Water

For experienced anglers and paddlers:

Fishing:

• Cheesman Canyon: Sight-fishing to large, selective trout. Requires stealth, 6X-7X tippet, and small flies (20-24)
• Fryingpan River: Outstanding hatches but demanding presentations. Trout refuse sloppy drifts.
• Gunnison Gorge: Remote wilderness fishing requiring significant hiking. Rewards with solitude and 20+ inch fish.

Paddling:

• Gore Canyon: Class V+ with mandatory portages. Expert-only or guided trips through Dvorak Expeditions.
• Upper Animas: Class IV-V above Silverton. Cold water, continuous rapids, remote access.
• Royal Gorge: Class IV-V. Commercial trips only for inexperienced paddlers.

Safety and Hazards

Cold Water

All Colorado rivers run cold. Tailwater temps rarely exceed 50°F. Hypothermia possible with extended immersion. The Blue River below Dillon runs 34-38°F year-round.

Spring Runoff

May through mid-June brings dangerous high water. Freestone rivers can run at several times normal volume. Cold, fast, debris-laden. Many rivers unfishable and unfloatable during peak.

Altitude

Most rivers sit above 6,000 feet; many above 8,000 feet. Acclimate before wading swift water or hiking into canyons.

Afternoon Thunderstorms

Summer afternoons bring lightning. Plan to be off exposed water by early afternoon.

River-Specific Hazards

• Arkansas Royal Gorge: Serious Class IV-V. Commercial only for non-experts.
• Upper Colorado: Bridge clearance issues above 5,500 CFS. Yarmony Rapid flips rafts at 2,500+ CFS.
• Gore Canyon: Class V+ with mandatory portages.
• Animas: Past mine-related water quality issues. Check current conditions.
• Gunnison: Sudden flow changes from dam releases.
• Cheesman Canyon: Poison ivy along riverbanks. Steep, loose trail.

Using RiverReports

RiverReports helps you time your Colorado trip:

• Check current flows against the ideal windows above
• Compare rivers: If your target is blown out, find alternatives in better shape
• Track trends: Rising, falling, or stable matters for trip planning
• Historical data: Understand typical conditions for your travel dates

Key Colorado gauges:

• Arkansas River at Salida
• South Platte at Deckers
• Colorado River near Kremmling
• Fryingpan below Ruedi Dam
• Animas at Durango

Download the RiverReports app for mobile access while on the road.

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