Above Moon Lake: Ashley National Forest
The Lake Fork rises under Mount Lovenia in the High Uintas and runs southeast to Moon Lake on the Ashley National Forest. The USGS gauge on this page (09289500) sits on this stretch above the reservoir, so it reads the unregulated snowmelt river, not the dam releases below. The road ends at the Moon Lake campground and trailhead; from there the Lake Fork trail follows the river into the High Uintas Wilderness. This is small, clear, wadeable water with a short season: it is running high with runoff through June and settles into shape in July.
Native Colorado River cutthroat live in the Lake Fork above and below Moon Lake down to the forest boundary. The Utah DWR notes some hybridization with rainbows and other cutthroat stocks in this reach, and the genetically pure population is in the Crater Lake outlet stream, a tributary that joins the Lake Fork above the reservoir. Farther in from the trailhead the fishing gets better and the company thinner.
Moon Lake Dam and the river below
Moon Lake Dam, built by the Bureau of Reclamation between 1935 and 1938 and operated since then by the Moon Lake Water Users Association, raised a natural lake into an irrigation reservoir for farms along the Lake Fork and Uinta rivers. Releases follow irrigation demand, not fishing: the river below the dam can run strong in early summer and drop to a trickle once the season ends. USGS gauge 09291000 just below the dam shows what is actually coming out. The Yellowstone Feeder Canal also takes water from the Yellowstone River, the Lake Fork's east fork, and sends it to the Uinta drainage, so the lower river is a managed system from the dam down. Moon Lake itself holds splake with a special limit.
Lower river: Mountain Home to Myton
Below the forest the Lake Fork flows through farm and ranch country past Mountain Home, picks up the Yellowstone River above the town, and joins the Duchesne River near Myton. Much of this lower river is on the Uintah and Ouray Reservation, where the Ute Indian Tribe has sole jurisdiction over fishing and a Utah license is not valid; you need a tribal fishing permit, and the tribe lists the Lake Fork as one of its designated rivers. Off the reservation the banks are largely private. The Utah DWR runs a fishing-only walk-in access property covering about 2 miles of the Lake Fork roughly 20 miles north of Duchesne, and a private lodge controls another stretch near Altamont. Check the DWR walk-in access map before you plan on any lower-river spot.
Colorado River cutthroat
The Lake Fork drains to the Duchesne and the Green, so its native trout is the Colorado River cutthroat, not the Bonneville cutthroat of the Great Basin side of the Uintas. Any cutthroat caught in a Green River tributary counts as a Colorado River cutthroat for the Utah Cutthroat Slam, and the DWR lists the Lake Fork above and below Moon Lake among the streams to try. These are small-stream fish that take attractor dries readily during the July to September window.
Brown, rainbow and brook trout
Below the dam the character changes. The lower Lake Fork is brown trout and rainbow water, with brook trout in the riffles and undercut banks along the meadow stretches. The Ute Tribe lists brown and rainbow as the sport fish of its Lake Fork reach, and the guides who work the lower private water report golden and dark stoneflies, caddis and mayflies through summer with a short mahogany dun hatch in August. Do not expect a tailwater with stable flows; the dam is an irrigation structure and the river below it rises and falls with the canals.
Season and regulations
No shop publishes a flow range for this gauge, so the 40 to 150 cfs range this page compares against comes from the USGS long-term monthly medians at 09289500 for July through October, the months the upper river is fishable. Above roughly 150 cfs the river above Moon Lake is still in runoff; the May and June medians run 250 to 450 cfs. This range says nothing about the regulated river below the dam, where gauge 09291000 is the one to watch.
On state and Forest Service water Utah's season runs all year, the statewide trout limit is 4 with no special rules listed for the Lake Fork in the 2026 guidebook, and a Utah license is required. On reservation trust land the Ute Indian Tribe's proclamation applies instead: in 2026 the Lake Fork is open to non-members from March 28 to September 9, a tribal permit (day or annual) is required for anyone 12 or older, fishing hours are a half hour before sunrise to a half hour after sunset, and non-member guiding is prohibited. Permits are sold by the tribe's Fish and Wildlife Department in Fort Duchesne. The tribe suspended all non-member permits in 2024 and restored them in 2025, so confirm the current proclamation and the current Utah DWR fishing guidebook before you drive out.