Troutline

Colorado River

Colorado·Western Slope·39.99° N, 106.43° W
Flow
80.9 CFS
Colorado R near Granby
Water Temp
45°F
Colorado R near Granby
Condition
Above Normal
Weather
42°F
Slight Chance T-storms

Insights

Lunar
New moon tonight
Dark nights — fish are more likely to feed through the day.
Flow
80.9 CFS — higher than typical
Push to the banks and softer water. Heavier flies.
Pressure
Pressure rising
Feeding may slow as fish sit tight.
Snowpack
Snowpack 10% of normal
Colorado River basin snowpack is at 10% of normal — expect an early runoff and low summer flows, with tailwaters and spring creeks holding up best. The May–July runoff forecast for Colorado R nr Cameo is 24% of average.

The Colorado River begins in Rocky Mountain National Park at La Poudre Pass Lake and runs through Grand Lake, Shadow Mountain, and Granby reservoirs before entering the fishable upper river around Granby and Hot Sulphur Springs. Below Windy Gap reservoir at Granby the river is heavily impacted by transbasin diversions — flows are often a fraction of natural at certain times of year. Below the Williams Fork confluence near Parshall the flows recover and the river becomes a serious wild brown trout fishery through Gore Canyon, the Pumphouse-Radium float section, and on through State Bridge to Glenwood Springs. Gold Medal designation runs from the Williams Fork confluence to the Troublesome Creek confluence near Kremmling.

The famous floats are Pumphouse to Radium (~5 mi) and Radium to Rancho del Rio (~5 mi) — Class II-III water with deep emerald-green pools, undercut banks, and willow cover. Best fishing is mid-July through October post-runoff. Pre-runoff Mother's Day caddis fishing in late April / early May can be exceptional on the Kremmling reach when flows are low and clear. Stoneflies (Pteronarcys) hatch in late June through Gore Canyon and the Pumphouse stretch. PMDs, caddis, and Yellow Sallies fish through summer; hopper-dropper through August-September; BWOs and streamers in October-November.

Kremmling is the corridor town with shops, outfitters, and Pumphouse-area BLM access. Hot Sulphur Springs serves the upper river. State Bridge and Rancho del Rio are the mid-river floating bases. Drive times: 2 hr from Denver to Kremmling (via I-70 + US-40), 1.5 hr from Vail to State Bridge. Hwy 9 parallels the river from Kremmling north toward Granby; CO-131 follows the mid-river from State Bridge to Wolcott. The river is big and pushy through the Gold Medal sections — drift boats are the norm; wading is limited to BLM access points at Pumphouse, Radium, and on the upper river above Williams Fork. Hoot-owl restrictions can apply on the mid-to-lower river in hot, low-water summers — check CPW updates.

Species

SpeciesAbundanceBest SeasonSizeNotes
Brown TroutAbundantJul-Oct12-22"Wild population dominant from Williams Fork down. Strong size class through the Pumphouse-Radium Gold Medal water. Streamer-aggressive in fall.
Rainbow TroutCommonJul-Oct10-18"Wild and stocked. Strongest on the upper river above Williams Fork and on the Glenwood Canyon stretch.
Mountain WhitefishCommonYear-round10-18"Native and abundant from Kremmling down. Aggressive nymph eats throughout.
Cutthroat TroutLimitedJul-Sep10-16"Native Colorado River Cutthroat in upper tributaries. Not a target on the mainstem.
Ideal wading flow700–2,500 CFS
Blow-out>4,500 CFS
Ideal water temp48–64°F

Mid-July through October post-runoff. Late June for stoneflies. Late April / early May for pre-runoff Mother's Day caddis. Streamer season Sep-Nov for pre-spawn browns. Upper river (Granby to Williams Fork) fishes more like a small-stream/tailwater hybrid and is best Jul-Sep when diversions allow flow.

Sections

6 sections on this river

Upper River — Granby to Williams Fork

WadeBrown Trout · Rainbow Trout

Upper river below the Granby reservoir complex through Hot Sulphur Springs to the Williams Fork confluence. Smaller water heavily affected by transbasin diversions — flows are dramatically variable. Mix of wild and stocked rainbows with some browns.

Best for: Rainbow trout and brown trout on small flies, BWOs, and PMDs. Best Jul-Sep when diversion flows are adequate.

Williams Fork to Troublesome Creek (Gold Medal)

Wade & FloatBrown Trout · Rainbow Trout

Thirteen-mile Gold Medal section below the Williams Fork confluence where flows recover. Strong wild brown trout fishery with regular fish to 22+ inches. Wading is excellent at Parshall and below; floating is the standard for covering water.

Best for: Wild brown trout and rainbow trout on caddis, PMDs, stoneflies, and streamers in fall. Best Jul-Oct post-runoff.

Pumphouse to Radium

FloatBrown Trout · Rainbow Trout

Five-mile Class II-III float through BLM Pumphouse-Radium recreation area. The classic Colorado River day-float — deep emerald pools, undercut willow banks, and strong brown trout populations. High summer recreation use (rafts, kayakers); fish early or late.

Best for: Wild brown trout on stoneflies (late Jun), hopper-droppers (Jul-Sep), and streamers (Sep-Nov). The Colorado's signature dry-fly water.

Radium to Rancho del Rio

FloatBrown Trout · Rainbow Trout

Five-mile float through narrower canyon below Radium. Less commercial pressure than Pumphouse-Radium. Continued Class II water with deep runs and pool tailouts. Holds bigger browns in the deeper slots.

Best for: Wild brown trout on streamers, stoneflies, and PMDs. Best Jul-Oct. Quieter float than Pumphouse-Radium.

State Bridge to Dotsero

FloatBrown Trout · Rainbow Trout

Below the Eagle River confluence the river broadens through Bond and Burns toward Dotsero. Bigger water, longer runs. Hopper-dropper float water with wild brown trout populations. Access at State Bridge, Bond, and Catamount Bridge BLM sites.

Best for: Wild brown trout on hopper-droppers and stonefly nymph rigs. Best Jul-Oct. Float-only practical for most of this stretch.

Glenwood Canyon — Dotsero to Glenwood Springs

Wade & FloatBrown Trout · Rainbow Trout · Whitefish

Spectacular canyon water through Glenwood Canyon — I-70 follows the river the whole way with bike-path and pull-out access. Mix of fast pocket water and deeper pools. Fishes well year-round; the most accessible stretch of the Colorado for day-tripping anglers from the I-70 corridor.

Best for: Wild brown trout, rainbow trout, and whitefish on nymph rigs, BWOs, and caddis. Year-round access; best Apr-Nov.

Regulations

Current fishing rules and restrictions

Gold Medal water from Williams Fork confluence to Troublesome Creek (about 13 miles). Gold Medal: 2 trout daily 16+ inches, artificial flies and lures only. Remainder of the river above and below: standard statewide trout limits (4 trout daily / 8 in possession).

  • Williams Fork confluence to Troublesome Creek (Gold Medal section, ~13 mi): artificial flies and lures only, 2 trout daily 16+ inches
  • Above Williams Fork: standard statewide limits (4 trout daily / 8 in possession)
  • Below Troublesome Creek through Glenwood Canyon: standard statewide limits
  • Below Glenwood Springs (Grand Junction area): standard statewide trout limits where coldwater, with mixed warmwater species in lower reaches

BLM Pumphouse and Radium recreation sites are managed for raft put-in/take-out and have permit/use-fee requirements for camping. The Colorado faces serious low-water years during drought — voluntary fishing closures are common in late summer below Kremmling when temperatures climb. The 1922 Colorado River Compact and modern transbasin diversions impact the upper river above Williams Fork dramatically; flows can swing widely.

Source: Colorado Parks & Wildlife — Fishing Regulations. Regulations change annually — verify before fishing.

Access & Logistics

Getting there, fly shops, and lodging

Getting There

Kremmling, CO (corridor town); Hot Sulphur Springs, CO (upper); State Bridge / Bond, CO (mid-river)

2 hr from Denver to Kremmling; 1.5 hr from Vail to State Bridge; 1 hr from Granby to Kremmling

Fly Shops

Lodges

  • Lazy Loon River Cabins (McCoy)

Camping & Lodging

BLM Pumphouse and Radium campgrounds (high summer demand, reservations recommended). Cabins and motels in Kremmling, Granby, and Hot Sulphur Springs. River-side lodging at Rancho del Rio, State Bridge, and Lazy Loon.

BLM boat ramps at Pumphouse, Radium, Rancho del Rio, State Bridge, Bond, Catamount, and Dotsero. Wading access on the upper river at Parshall, Williams Fork confluence, and Hot Sulphur Springs (Pioneer Park). Hwy 9 follows the upper river; CO-131 follows the mid-river. Cell coverage spotty between Kremmling and State Bridge.

Conditions data is live from public monitoring networks. Regulations change annually — always verify current rules with your state fish & wildlife agency before fishing.

More in Colorado

View all 8 rivers

Western Slope

Blue RiverCO

Summit County tailwater below Dillon Reservoir through Silverthorne, then a longer reach below Green Mountain Reservoir down to its confluence with the Colorado. The Outlets Mall stretch in Silverthorne is the most-fished stretch — urban, accessible, and selective. Below Green Mountain offers bigger drift-boat water with strong wild brown trout populations.

Eagle RiverCO

Freestone running 75 miles from Tennessee Pass near Leadville through Minturn, Vail, Avon, Edwards, and Eagle to the Colorado River at Dotsero. Heavily affected by historic mining at the Eagle Mine but recovering — fall brown trout fishing through Edwards and Wolcott is the best of the year.

Frying Pan RiverCO

Fourteen miles of legendary Gold Medal tailwater below Ruedi Reservoir, ending at the Roaring Fork in Basalt. Mysis shrimp from the reservoir grow huge trout — 'Toilet Bowl' fish below the dam are some of the largest wild rainbows in the lower 48.

Gunnison RiverCO

Big-water Gold Medal fishery best known for the Gunnison Gorge — 14 miles of wilderness canyon below the Black Canyon with the densest population of large wild trout in the state. Easier float-and-wade fishing on the lower river through Delta and Whitewater.

Roaring Fork RiverCO

Gold Medal freestone running 70 miles from Independence Pass through Aspen, Basalt, and Carbondale to the Colorado River at Glenwood Springs. Big-river hopper-dropper water below Basalt and the Crystal River confluence; tighter pocket water through Aspen.

Other regions

Arkansas RiverCO

102 miles of Gold Medal water from Leadville to Parkdale — Colorado's longest continuous Gold Medal stretch. A high-elevation freestone with strong caddis hatches, a stout summer guide industry, and excellent walk-and-wade access along Highway 24 and Highway 50.

South Platte RiverCO

Colorado's most-fished trout river — three Gold Medal tailwaters within ninety minutes of Denver. Cheesman Canyon and Deckers below Cheesman Reservoir, and the 'Dream Stream' between Spinney Mountain and Elevenmile reservoirs in South Park, are the destination water.