Colorado River near Kremmling
Fishable
Flow468 CFS
Trendrising
Clarityslightly stained
Temp50°F
Pat's Rubber Legs #6-10Chubby Chernobyl #10-14Sparkle Dun PMD #18Beefus Emerger #18-22
Floating the Upper Colorado in Summer
CO
beginner
Current Conditions
Live flows, verdict, and fishing reportQuick Reference
| What | When | Key Numbers |
|---|---|---|
| Pumphouse to State Bridge | July-Sept | 14 mi; 4-6 hrs; Class I-II; Gold Medal water |
| Ideal floating flows | July-Aug typical | 1,500-3,300 CFS; below 1,000 better for fishing |
| Gold Medal fishing | Year-round (July-Sept prime) | 4,000-5,000 trout/mile; 16-17" common |
| Camping | Reserve via Recreation.gov | Pumphouse $25/night + $10 day use (eff. July 2025) |
| Shuttle | Rancho del Rio | $50-105; vehicles ready by 1pm |
| Guided fishing | Book ahead for July-Aug | $500-650/day; Mountain Angler |
GOOD
Updated yesterday
Flows at 468 CFS at the Kremmling gauge as of May 22, up from 330 CFS on May 19 and 220-230 CFS on May 16 — early runoff is slowly arriving. Water temp 50.4°F (USGS). Turbidity at 18.5 FNU, giving the water slight color from early snowmelt — a change from the gin-clear conditions of the past few weeks. Still dramatically below normal for late May (typical runoff: 2,000-4,000+ CFS). NOAA continues projecting record-low inflows; 2026 flows running at roughly 25% of normal. Fishing remains excellent — fish concentrated and feeding aggressively in the low water. Salmonfly emergence in full swing: adults collecting on streamside vegetation and rocks, with fish keying on both nymphs and dries. Pat's Rubber Legs #6-10 the go-to subsurface stonefly pattern; Chubby Chernobyl #10-14 and Stimulator #8-12 working as salmonfly dry fly imitations. PMDs remain the dominant mayfly hatch — Sparkle Dun PMD #18 and Parawulff PMD #16 producing reliable surface takes from 11am-2pm. BWOs strong on overcast afternoons; Beefus Emerger #18-22 and Parachute Adams #16-20. Caddis active on warm afternoons and evenings: Hot Mess Caddis and Elk Hair Caddis #16-18. Midges constant: olive Zebra Midges, Black Rainbow Warriors #18-22. Nymphing still the most consistent method: lead with Pat's Rubber Legs #6-10 or Mercer's Poxyback Micro Stone #14-18, trail with Tungsten Slim Shady BWO #18-20 or Pheasant Tail #14-20. Streamers effective for aggressive browns — Dungeons, Heisenbergs, Barely Legal, Sparkle Minnow through deeper pools. Way too low to float (need 1,500+ CFS). Wade fishing outstanding at Pumphouse through Rancho del Rio — historic low water continues to expose rarely accessible structure. Watch for increasing turbidity as runoff builds over the next 1-2 weeks. Spawning creek closures through May 31 (Grizzly, No Name, Canyon, Elk Creeks). Best window 11am-2pm. 5X-6X fluorocarbon tippet; 6X for dries.
🎣 TACTICS RIGHT NOWWade fishing at 468 CFS — flows rising as early runoff arrives, up from 330 CFS on May 19. Water temp 50°F with slight stain from snowmelt (18.5 FNU turbidity). Best window 11am-2pm as water warms into the mid-50s. Salmonfly emergence in full swing — adults on streamside rocks and vegetation. Lead with Pat's Rubber Legs #6-10 or Mercer's Poxyback Micro Stone #14-18, trail with Tungsten Slim Shady BWO #18-20 or Pheasant Tail #14-20. Switch to dry-dropper with Chubby Chernobyl #10-14 or Stimulator #8-12 as salmonfly dries — fish are eating adults off the surface. PMDs producing reliable rises from 11am-2pm: Sparkle Dun PMD #18 or Parawulff PMD #16. Caddis excellent on warm afternoons: Hot Mess Caddis and Elk Hair Caddis #16-18. Streamers effective for browns — Dungeons, Heisenbergs, Barely Legal, Sparkle Minnow through deeper pools and undercuts. The slight stain from early melt actually helping streamer fishing — less spooky fish. Still historically low water with outstanding wade access to structure not normally exposed. 5X-6X fluorocarbon tippet (6X for dries). Move slow and stay low.
Dry Fly
Sparkle Dun PMD #18Parawulff PMD #16Beefus Emerger #18-22Garcia's Mini Hot May #18-22Parachute Adams #12-22Elk Hair Caddis (olive/brown/yellow) #12-18Hot Mess Caddis #16-18Black Sedge Caddis #16-22CDC Baetis Dun #18-22Morgan's CDC Midge #20-24Chubby Chernobyl #10-14Renegade #14-18
Nymph
Pat's Rubber Legs (black/olive/coffee) #6-14Mercer's Poxyback Micro Stone (dark) #14-18TDJ Golden Stone #14-18Tungsten Slim Shady BWO #18-20Tungsten Flashback Pheasant Tail #14-20Zebra Midge (olive) #18-22Black Rainbow Warrior #18-22Sparkle Wing RS2 #18-22Hare's Ear #12-18Chronic Caddis (tan/olive) #14-16Perdigon (purple/pink) #14-20Red/Pink Worms
Streamer
Dungeons (cream/black/gray)Rainbow/Black HeisenbergBarely Legal (white-olive/grey-white)Sparkle MinnowSculpzilla #4-6Baby GongaWoolly Buggers (olive/black) #8-12Black Slumpbusters #4-6Leeches (wine/black) #6-8
FORECASTFlows at 468 CFS (May 22), up from 330 CFS on May 19 — early runoff is arriving but remains extremely muted. River running at roughly 25% of normal for late May (typical: 2,000-4,000+ CFS). NOAA continues projecting record-low inflows to Lake Powell. Turbidity has ticked up to 18.5 FNU, giving the water slight color from snowmelt contributions — expect turbidity to increase further over the next 1-2 weeks as whatever runoff exists works through. Summer floating window (1,500+ CFS) very unlikely this year barring exceptional monsoon rain; plan exclusively for wade fishing. Salmonfly emergence now in full swing — peak adult activity through late May into early June with dry fly opportunities on stonefly patterns. Golden stonefly emergence to follow in June. PMDs dominant, caddis active, BWOs reliable on cloudy days. Water temp 50°F and trending warmer — expect mid-50s to low 60s through late May. Spawning creek closures through May 31 (Grizzly, No Name, Canyon, Elk Creeks). Summer concern remains: record-low flows mean warmer water and fish stress arriving significantly earlier than usual. Outfitters planning early-morning-only trips for summer. Water temp closures could come as early as late June at these flow levels. Carry a stream thermometer. Hopper season likely arriving late May to early June given warm, dry conditions. The slight stain in the water is actually beneficial for streamer fishing and reducing fish spookiness. Upside: historically rare wade fishing access with fish concentrated in pools and runs; fishing quality remains excellent per local fly shops.
Overview
The Upper Colorado River from Pumphouse to Dotsero is one of Colorado's best summer float trips. This 60+ mile stretch offers Class I-II water through scenic BLM canyon lands - ideal for family floats, multi-day camping trips, or serious fly fishing.
What sets this section apart: it holds Gold Medal water designation. CPW electrofishing surveys find 4,000-5,000 trout per mile in the Pumphouse to Catamount section, with 16-17 inch fish common. The largest brown ever documented here was 17 pounds.
Summer (July-September) is prime time. Runoff has subsided, flows settle into ideal ranges, and the canyon sees less crowding than Colorado's more famous rivers. The catch: no cell service from Pumphouse through the canyon, so plan accordingly.
Flow Windows
Understanding flows is essential for timing your trip. Check Colorado River flows near Kremmling before launching.
| Flow (CFS) | Conditions |
|---|---|
| Under 600 | Low water - scraping likely, slower float, some portaging possible |
| 600-1,000 | Prime fishing flows - Class II rapids become gentler Class I-II, excellent wade access |
| 1,000-1,500 | Low-normal floating - relaxed pace, some shallow spots |
| 1,500-3,300 | Ideal floating range - good current, Class II rapids run clean |
| 3,300-5,500 | Higher water - faster, more technical, experienced paddlers only |
| Over 5,500 | High water - bridge clearance issues at second bridge, significant hazards |
The ideal floating window of 1,500-3,300 CFS typically occurs from late June through mid-August. By late August and September, flows often drop below 1,000 CFS - still floatable but slower, with better fishing conditions.
Key Sections
Pumphouse to Radium (4 miles)
The most popular short float, taking 2-2.5 hours at typical summer flows.
Rapids:
- Wake Up Rapid (Class II) - straightforward warm-up at river mile 1
- Needle's Eye (Class II) - the signature rapid with a narrow chute through a rock garden. Scout from river-left if unfamiliar.
- Mary's Wall - immediately after Needle's Eye, the river pushes right into a cliff. Stay left at all water levels.
Takeout bonus: Radium Hot Springs and Jump Rock are at the takeout - natural warm springs tucked against a popular cliff jumping spot.
Radium to Rancho del Rio (6 miles)
Longer section through the canyon with consistent riffles and a more remote feel. Takes 3-4 hours.
Rapids:
- Red Eye Rapid (Class II-III at higher flows) - most significant feature in this section
- Yarmony (Hoyt) Rapid (Class II, up to III at 2,500+ CFS) - the most consequential rapid on the upper stretch. At higher flows, a large boulder creates a hole that can flip rafts. Stay center-right to avoid the hole.
Nine on-river primitive campsites are available first-come, first-served through this section.
Rancho del Rio to State Bridge (4 miles)
The mellower finish to a Pumphouse-State Bridge day float. Mostly Class I-II water. Takes 1.5-2 hours.
Total Pumphouse to State Bridge: 14 miles, 4-6 hours depending on flow and fishing stops.
State Bridge to Dotsero (45 miles)
The lower stretch sees far less traffic and is typically done as a multi-day trip. Character changes to wider, mellower water through ranch country.
| Section | Distance | Float Time | Notes |
|---|---|---|---|
| State Bridge to Catamount | 16 miles | 6-7 hours | Class I-II, mellow, great camping |
| Catamount to Pinball | 9 miles | 4-5 hours | Remote, Bull Gulch WSA |
| Pinball to Dotsero | 20 miles | 8-10 hours | Long day or split into two |
Rapids Below State Bridge:
- Windy Point (Class II) - only named rapid in the upper portion
- Alkali (Class II) - below Catamount
- Landslide/Rodeo Rapid (Class III) - solid drop, easy to scout from road if needed
- Pinball Rapid (Class III) - fun wave train
- Twin Bridges (Class II+) - marks end of the scenic canyon stretch
Why do the lower stretch? Solitude. You'll likely have the river to yourself, and the camping at Jacks Flat is considered by many the best on the entire Upper C - a quiet site with a natural berm blocking road and railroad noise.
Access Points & Logistics
All access points are managed by BLM Kremmling Field Office. Note: New fee structure takes effect July 7, 2025.
Pumphouse Recreation Site (Primary Put-in)
- Three boat ramps (Launch 3 is ADA accessible)
- 18 individual campsites - $25/night (reservations required via Recreation.gov)
- 2 group campsites - $75/night
- Vault toilets, drinking water (summer only - not always operational)
- Day-use parking: $10 per vehicle (vehicle season pass: $50)
- Camp host on-site during summer
- No cell service - Kremmling (15 miles) is nearest town for supplies
Radium Recreation Site
- Mid-river access with two launch areas
- 9 standard campsites - fees similar to Pumphouse
- Good swimming at Radium Hot Springs adjacent to takeout
Rancho del Rio
- Private lodge/campground with river access
- Restaurant, general store, cabins
- Shuttle service available (see below)
State Bridge
- Concert venue and lodge with restaurant, cabins, general store
- Day-use: $10 per vehicle
- Paved boat ramp
- 14 miles from I-70 (Wolcott Exit #157)
Lower Section Access (State Bridge to Dotsero)
Six BLM-maintained access points allow trip customization:
- Catamount - vault toilet, fire rings, picnic tables
- Pinball Point - similar facilities
- Windy Point - camping with toilet and fire rings
- Cottonwood & Lyons Gulch - developed campsites
- Jacks Flat - wilderness-style camping (bring your own toilet system)
- Dotsero - final takeout before Glenwood Canyon
Getting There
From Denver (2 hours): I-70 west to Exit 205 (Silverthorne), Highway 9 north through Kremmling, then Trough Road (County Road 1) west for 10 miles to Pumphouse.
From Vail (45 minutes): I-70 to Exit 157 (Wolcott), Highway 131 north for 12 miles to State Bridge.
Road conditions: Trough Road is maintained gravel, passable for most vehicles in dry conditions. Can get rough after rain - high clearance helpful but not required.
Shuttle Services
Most floaters run a two-vehicle shuttle. If you only have one vehicle:
Rancho del Rio - (970) 653-4431
- Shuttles from Pumphouse to State Bridge and other combinations
- $50-105 depending on route
- Vehicles must be at put-in by 1:00pm for same-day service
- Book online at ranchodelrio.com
AVA Rafting - coloradorafting.net
- Shuttle service from Kremmling outpost
- Add to raft rental bookings
Tip: Day-use fees apply at both put-in and take-out, including shuttled vehicles.
BLM Contact: Kremmling Field Office - (970) 724-3027
Summer Fly Fishing
The Upper Colorado fishes well all summer, with different patterns emerging as conditions change.
July: Post-Runoff Prime Time
Water clarity improves dramatically once runoff subsides. Golden Stoneflies follow the salmonfly hatch, with peak activity in the first two weeks of July. This is arguably the best month for dry fly fishing.
Key Hatches:
- Golden Stoneflies (#8-12) - fish dries and nymphs
- Yellow Sallies (#14-16) - Mercers Micro Stone
- Caddis (#14-18) - evening hatches produce rising fish
- PMDs (#16-18) - late morning to early afternoon
August: Hopper Season
As flows drop below 1,000 CFS, the river reveals rock gardens and sandy bars perfect for hopper-dropper rigs. Fish move into shallower water along willow-lined banks.
Key Hatches:
- Terrestrials (hoppers, beetles, ants) - work the banks
- Yellow Sallies continue
- Caddis (#16-18) - consistent evening activity
- Tricos (#20-24) - early morning spinners
September: Fall Transition
Cooler nights trigger renewed mayfly activity. Brown trout become more aggressive as spawn approaches.
Key Hatches:
- BWOs (#18-22) - afternoon hatches on cloudy days
- Streamers become increasingly effective
- Midges (#20-24) - consistent subsurface food source
Fly Box Essentials
Dries:
- Elk Hair Caddis (#14-18, tan and olive)
- Yellow Stimulator (#14-16)
- Schroeder's Parachute Hopper (#8-12)
- Parachute Adams (#16-20)
- Chubby Chernobyl (#10-14)
Nymphs:
- Pat's Rubberlegs (#6-10, black/brown)
- Pheasant Tail (#16-18)
- Hare's Ear (#14-16)
- RS2 (#18-22)
- Zebra Midge (#18-22)
Streamers:
- Woolly Bugger (#6-10, olive and black)
- Slumpbuster (#4-6)
- Sculpzilla (#4-6)
Wade vs. Float Fishing
Float fishing covers more water and accesses private stretches between public access points. Best when flows are 800-2,000 CFS.
Wade fishing becomes excellent as flows drop below 1,000 CFS in late summer. Rock gardens and gravel bars emerge, allowing access to runs that were unreachable earlier. Best access points for wading:
- Below Pumphouse boat ramp
- Radium area
- BLM pullouts along Trough Road between State Bridge and Catamount
Best Times of Day
- Early morning (6-9am): Cooler water, active fish, Trico spinners in August
- Late morning (10am-noon): PMD activity, comfortable air temps
- Evening (6-8pm): Caddis hatches, rising fish, best dry fly window
Water Temperature Warning: Stop fishing when water temps reach 68°F. Trout become stressed above 65°F and mortality risk increases even with careful handling. Carry a stream thermometer - afternoon temps can spike during July heat waves.
Hazards
High Water (Flows above 3,300 CFS)
- At flows over 5,500 CFS, you cannot float under the second bridge
- Yarmony Rapid becomes a serious Class III with a boat-flipping hole
- Cold water persists even when air temps are warm
- Faster current means less reaction time for obstacles
Strainers (Downed Trees)
Strainers accumulate on outside bends after high water events. Scout any unfamiliar sections. If swimming and you can't avoid a strainer, turn onto your stomach and climb up and over - never swim underneath.
Weather
Afternoon thunderstorms are common July-August. Plan to be off the water by early afternoon if storms are forecast. Lightning is the primary danger.
No Cell Service
There's no cell coverage from Pumphouse through the canyon to State Bridge. Plan accordingly:
- Tell someone your float plan and expected return
- Bring a satellite communicator (Garmin InReach) for emergencies
- Know basic self-rescue techniques
Overnight Trip Requirements
For on-river camping, BLM requires:
- Fire pan for any campfires
- Leak-proof human waste containment system (WAG bags)
- Pack out all trash
Gear Recommendations
Floating Essentials
- Coast Guard-approved PFD for each person
- Dry bag for valuables and dry clothes
- Water and snacks (plan for full-day hydration)
- Sun protection - hat, sunscreen, polarized sunglasses
- River sandals or water shoes
- Throw rope (50+ feet)
Fishing Gear
- 9' 5-weight rod (good all-around choice)
- 9' 4-weight for dry fly work in late summer
- Floating line with 9' 4X-5X leader
- Stream thermometer
- Waders for early morning/cool days (late summer you can wet wade)
Multi-Day Additions
- Fire pan
- WAG bags or portable toilet system
- Water filter
- Tent, sleeping gear
- Cooler for food (dry ice lasts longer than regular ice)
- Camp chair
- Headlamp
- Bug spray (mosquitoes can be heavy at Jacks Flat)
Seasonal Summary
| Month | Typical Flows | Conditions | Best For |
|---|---|---|---|
| Late June | 2,000-3,500 CFS | Dropping from runoff | Experienced floaters, late salmonflies |
| July | 1,200-2,500 CFS | Prime floating | Everyone - best balance of current and safety |
| August | 600-1,200 CFS | Lower, slower | Fishing, families, multi-day trips |
| September | 400-800 CFS | Low water | Wade fishing, fall colors, solitude |
The Upper Colorado has a longer season than many Colorado rivers, often remaining floatable into late September when other rivers have dropped too low.
Guided Options
Rafting Outfitters
AVA Rafting - coloradorafting.net
- Operates from Kremmling outpost
- Half-day scenic floats, ages 2+
- Raft rentals from $199
Colorado River Rentals - coloradoriverrentals.com
- Self-guided raft rentals with shuttle service
Rancho del Rio - ranchodelrio.com
- Shuttle service and trip support
Fly Fishing Guides
Mountain Angler (Breckenridge) - mountainangler.com
- Permitted on 50+ miles from Pumphouse to Dotsero
- Exclusive access at Yellow Dog Ranch
Kirks Flyshop (Grand Lake) - kirksflyshopgrandlake.com
- Half-day ($500) and full-day ($650) float trips
- All gear provided including lunch on full days
Vail Valley Anglers - vailvalleyanglers.com
- Detailed fishing reports on current conditions
Using RiverReports
Plan your trip with real-time data:
- Colorado River near Kremmling - primary gauge for this stretch
- Compare current flows to seasonal averages
- Set flow alerts to know when conditions hit your target window
- Check the 7-day forecast to time your trip
The Upper Colorado's natural flow pattern means conditions can change more quickly than dam-controlled rivers. Check flows within 24-48 hours of your trip, not just a week out.
For June floating during runoff season, see our Upper Colorado June Guide. For statewide conditions, visit Colorado rivers.
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