What flies work best on Williams Fork River?

Midges and Baetis nymphs are the most consistent producers on the Williams Fork tailwater year-round. RS2, Zebra Midge, and Tungsten Baetis patterns in sizes 18-22 cover most situations. PMD patterns work well in summer. Elk Hair Caddis and stonefly nymphs are effective in the warmer months. Streamers including Sculpzilla and Pine Squirrel Leech produce well in the deeper pools especially in fall and winter.

Williams Fork River Fishing Conditions & Report

Williams Fork River

Colorado · Grand County — Williams Fork Reservoir to Parshall

Brown TroutRainbow Trout

Top Fishing Locations on Williams Fork River

Tailwater — Below Williams Fork Reservoir

The 2-mile catch-and-release tailwater below Williams Fork Dam is where the Willy's Fork earns its reputation. Cold reservoir releases keep water temperatures in the trout zone year-round and the browns and rainbows in here run 20 to 24 inches in the better holes. Two access points both require about a mile walk — from the DOW parking area at County Roads 3 and 36, or from Highway 40 in Parshall crossing the Colorado River. The walk keeps pressure light. Cottonwood-lined banks, deep runs, pools, and pocket water in a two-mile stretch that feels much larger than it is. The hike is worth it.

💧 Ideal flow: 100 to 300 CFS. Denver Water controls releases and flows can change without much warning. Check the gauge before making the drive — low flows under 50 CFS push fish into deep structure and make fishing technical. High flows above 400 CFS can muddy the water and make wading difficult on the cobblestone bottom.

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Colorado River Confluence — Parshall

Where the Williams Fork meets the Colorado River in Parshall the two rivers create a productive zone where trout from both systems hold. At good flows fish push up from the Colorado into the Williams Fork and the confluence pool holds good numbers. Access from the Highway 40 bridge in Parshall is the easiest entry point on the system. The upper Colorado River above and below Parshall is well worth fishing in combination with a Williams Fork trip — the stretch of Colorado River through this area holds some of the best dry fly water in Grand County.

💧 Ideal flow: fishes well across a range of conditions at the confluence. High Williams Fork flows can color the water at the confluence — check both gauges. The Colorado River above Parshall fishes consistently regardless of Williams Fork conditions.

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About Williams Fork River Fishing

The Williams Fork River — the Willy's Fork to guides and regulars — starts from the Continental Divide just west of Berthoud Pass, flows through Arapaho National Forest, and collects in Williams Fork Reservoir before releasing as a 2-mile tailwater into the Colorado River near Parshall. That 2-mile tailwater is one of Colorado's more underappreciated fisheries. It sees a fraction of the pressure that hits the South Platte, Frying Pan, or Blue River, yet holds browns and rainbows running 20 to 24 inches in the better pools. The catch is the hike — about a mile to reach the water from either access point. Most Colorado anglers can't be bothered. That's what keeps it good.

Best Time to Fish the Williams Fork

Summer and fall are the top seasons. July through September the tailwater fishes dry flies well with good PMD and caddis hatches, and streamers work in the deeper pools throughout. Fall brings aggressive browns pre-spawn and streamer fishing picks up significantly in October. Winter midge and Baetis fishing is productive for the anglers willing to make the hike in cold weather — the tailwater stays open year-round and fish stack in the pools during winter. Spring runoff from May through mid-June can color the water — check conditions before going. Always check flows before making the drive. Denver Water controls releases and the gauge can swing significantly without much notice.

Species

Brown trout and rainbow trout in the tailwater, with occasional cutthroat. The tailwater holds a good population of wild fish supplemented by the reservoir system. Browns run to 24 inches in the deep pools and runs near the dam. Rainbow trout average somewhat smaller but fight hard in the cold tailwater flows.

Access and Regulations

Two access points for the tailwater — both require approximately a 1-mile walk. From Parshall on Highway 40, cross the Colorado River and hike to the confluence. Or take County Road 3 south from Highway 40 to the DOW parking area at County Roads 3 and 36, then follow the marked trail about a mile to the river. The 2-mile section nearest the dam is catch-and-release. Colorado fishing license required. Check current Colorado Parks and Wildlife regulations before fishing. Denver Water controls flows — always check the USGS gauge before making the trip as conditions can change significantly.

Live River Data

Streamflow data is pulled in real time from the USGS National Water Information System. The Williams Fork gauge reflects releases controlled by Denver Water — flows can change with little notice. The river fishes best between 100 and 300 CFS. Below 50 CFS fish go deep and presentations get technical. Above 400 CFS wading becomes difficult on the cobblestone bottom.