DIY Guide to Fly Fishing the Williams Fork River in Colorado

For those fly fishermen that long for the quiet stream amidst rolling hills far from highways and foot traffic, the Williams Fork River is an answered prayer to anglers plying the Upper Colorado.

This off-the-beaten track river is the ideal size for rainbows, browns, and the occasional cutthroat, and is easily wadeable from either bank.

While the nearest parking access to Williams Fork is a good 30 minute hike to the river, one can usually traverse the level terrain via mountain bike in less than half that time, and there are no ridiculous downhill stretches to negotiate either.

The Williams Fork makes its headwaters by the Continental Divide just west of Berthoud Pass, flowing parallel to the Blue River. The Blue and Williams Fork are both tributaries of the Colorado River itself, with the Williams Fork passing through Arapaho National Forest. While the river itself is over 45-miles in length, the most storied section of water is the 2-mile tailwater below Williams Fork Reservoir.

Williams Fork Reservoir is easily accessible from Highway 40 near the town of Parshall. Here below the reservoir dam the browns and rainbows strike at dry flies like it’s their job, and the Division of Wildlife leases access to the water at Kemp and Breeze State Wildlife Area. Water levels do tend to fluctuate a bit depending on the needs of the Denver Water Board. 

Williams Fork River Map, Fishing Access Sites and Boat Launches

map of fishing access spots on the Williams Fork River in Colorado

Get directions to fishing access points and real-time stream flow data with the DIY Fly Fishing Map

Best Places to Fish the Williams Fork River

If you want to fish closer to the headwaters of the Williams Fork, you will need to take Highway 40 west of Granby, or alternatively you can start in Kremmling by the airport there and head east.

Most anglers park in or near Parshall and start along the Williams Fork River nearest its confluence with the Colorado River. Plenty of quiet scenic fishing to be had along the banks of the river here, and you can even follow the river as far as Arapaho National Forest if you don’t mind the hike or the drive.

Anglers keen to land the big browns and rainbows below the Williams Fork Reservoir should take County Road 3 from Parshall south until you see the Division of Wildlife Parking area about a third of a mile or so from the Colorado River.

From the parking area, it's about a mile's distance on foot to get to the Williams Fork along a clearly marked path. Remember that the two miles of river in this area nearest the Williams Fork Reservoir are catch-and-release only, so plan your visit accordingly.

Keep in mind that flow rates and depth here vary depending on the needs of the Denver Water Board, so definitely check local conditions before heading out. The river fishes best at flows between 100 and 300 cfs.

Williams Fork River Flow and Current Conditions


  • Flow: 16.6 ft³/s
  • Water Level: 0.81 ft

Best Time to Fish the Williams Fork River

Fishing is year round on the Williams Fork, and there really isn’t a time of year when the fish aren’t feeding, especially when midges are thickest in the late fall and winter months. Even better, conditions remain ideal between 9 a.m. to 6 p.m. pretty much year round, so there is no need to start or finish your day early on the Williams Fork.

If winter fly fishing isn’t really for you, the BWO, Caddis, and stone fly hatches are similarly excellent in terms of population and popularity with the local trout, too. Make sure you match the hatch as best you can based on the time of year your visit.

Best Flies for Williams Fork River

Midges, BWOs, Caddis, and stoneflies are the patterns of choice here.

Recommended fly patterns organized by order of importance include:

- English Pheasant Tail (black #14-18)
- Pale Morning Dun Thorax (brown/black #16-20)
- RS2 (gray #20-22)
- Blue Wing Olive Parachute (olive #18-22)
- WD-40 (black/olive/brown #20-24)
- Woolly Bugger (black#12)
- Pat's Rubber Legs (black/brown #10-12)
- Slump Buster (black/natural/olive 6-8)
- Buckskin (natural #20-22)
- San Juan Worm (pink/tan/ted #12)

Need flies? 

Ventures Fly Co. offers a great selection of dry flies, nymphs and streamers that will catch fish just about anywhere.  Set includes 40 high quality, hand-tied flies (see list below) and waterproof fly box. 

Dry Flies
- Adams Dry Fly
- Elk Hair Caddis
- Blue Wing Olive
- Royal Wulff
- Griffith's Gnat White
- Stimulator, Organge
- Chernobyl Ant

Nymphs/Wet Flies
- Rubber Leg Nymph, Brown
- BH Pheasant Tail Nymph
- BH Prince Nymph
- BH Hare's Ear Nymph
- Barr's Emerger Nymph
- Zebra Midge Nymph, Black

- Wooly Bugger, Black (Size #8x2)
- Wooly Bugger, Olive (Size #8x2)

Williams Fork River Fishing Tips

A 9-foot 5-wt fly rod with floating line is perfect for fishing dry flies and small nymphs on the Williams Fork River. A tapered 9-foot leader, with tippet size 3X to 6X to match the flies you are throwing, is pretty standard. Waders are a must for the Williams Fork if you want to get the best results.

Need Gear? 

Below are recommendations for essential gear to make the most of your time on the water.  Note: DIY Fly Fishing earns a commission (at no cost to you) on sales made using the links below.  Thank you for your support!

Williams Fork River Fishing Reports

Williams Fork River Fishing Regulations

As far as CDOW regulations go for Williams Fork, anything above the reservoir is standard regulations: 4 fish any species up to 20 inches, and all waters below the dam are catch-and-release only. The catch-and-release only section is well marked.

Williams Fork River Trip Planning Tips

Airport access for the Williams Fork is plentiful, with Denver International Airport, Kremmling, and Eagle all providing flights to and from the area closest to the river itself. Accommodations are plentiful in Parshall, and Boulder is roughly an hour and a half drive from there if you are looking for greater variety in a place to stay. You can also rent fishing and hunting cabins in the area around Parshall, and it’s always a good idea to check into local vacation rentals as well, since these can yield some promising bargains when skiing is out of season in and around Boulder.

Looking for more places to fish? Visit our DIY Guide to the Best Fly Fishing in Colorado.

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