Wyoming holds most of Yellowstone National Park, all of Grand Teton, and the headwaters of three great river systems: the Snake, the Green and the North Platte. It also has its own cutthroat. The Snake River fine-spotted cutthroat is native to Jackson Hole and the upper Snake, the Yellowstone cutthroat to the Lamar and Yellowstone Lake, and the state's fishing is organized around them. Wyoming is a freestone state with a few important tailwaters; runoff peaks in June, the park's high meadow streams do not come into shape until July, and the North Platte and Green tailwaters carry the spring.
Yellowstone National Park: the Firehole, the Lamar and the Gibbon
The Firehole River is a trout stream that flows through geyser basins, and thermal inflow gives it hatches earlier than anything else in the park. Blue-Winged Olives, Pale Morning Duns and caddis come off in June along Fountain Flats and the Midway Geyser Basin, and browns and rainbows rise to them among the steam vents; by mid-July the same thermal water gets too warm and fishing shifts to September and October. The Lamar River in the Lamar Valley is the opposite: a big meadow freestone that stays muddy from snowmelt and thunderstorms until July, then fishes for Yellowstone cutthroat on hoppers, Golden Stones and caddis through September, with bison and wolves as scenery. The Gibbon River above Gibbon Falls holds brook trout and grayling in small meadow water. Yellowstone Lake is the center of a long effort to restore native cutthroat by removing lake trout. Every water inside the park is fished on the park's own permit and regulations, separate from the state's.
The Snake in Jackson Hole
The Snake River from Pacific Creek in Grand Teton National Park down through Moose, South Park and Hoback Junction to Alpine is a braided, fast float fishery for fine-spotted cutthroat that eat dry flies with an enthusiasm the fish in neighboring states have lost. Salmonflies in June, Golden Stones through July, Pale Morning Duns in July, and a grasshopper season from July into September make it a Chubby Chernobyl and Stimulator river, #4 to #10. Flows of 1,000 to 8,000 cfs on gauge 13010065 are all fishable from a boat; wading is limited to side channels. Jackson Lake at the head of the valley holds lake trout and cutthroat. The Gros Ventre, Hoback, Greys and Salt rivers, all gauged Snake tributaries, are good cutthroat water without guide pages yet.
The North Platte: the Miracle Mile and Saratoga
The North Platte River in south-central Wyoming is the state's most productive brown trout river. The Miracle Mile below Kortes Dam is a tailwater with heavy fish and a spring window when the tailwaters are the only game; the upper river through Saratoga and up toward Encampment is a freestone with a Salmonfly hatch in June and Golden Stones into July that anglers plan around. Below Gray Reef Dam near Casper, the river becomes another well-known tailwater reach that this site has not written up yet. Midges and Blue-Winged Olives carry the cold months on the Mile, with Zebra Midges and Brassies in #18 to #22. The Encampment River, gauged with temperature, is the North Platte's best small tributary; the Laramie and Medicine Bow, also gauged, drain the same country.
The Green below Fontenelle and the Wind River Range
The Green River begins in the Wind River Range and by the time it reaches Fontenelle Dam near La Barge it is a tailwater with rainbows and browns, fishing well from June through October on Pale Morning Duns, caddis and hoppers. Upstream, the New Fork River drains the west slope of the Winds through Pinedale toward Big Piney and holds fine-spotted cutthroat and browns in a freestone that clears in late June. Fremont Lake above Pinedale is a deep glacial lake known for lake trout. On the east side of the Winds, the Wind River itself, gauged with temperature, runs through the Wind River Reservation, where fishing requires a tribal permit, before becoming the Bighorn at the Wedding of the Waters near Thermopolis.
Cody country: the Shoshone and the Bighorn
The Shoshone River below Buffalo Bill Dam runs through a canyon and then through the town of Cody as a tailwater with browns and rainbows, fishing best in June, July, September and October on caddis, Pale Morning Duns and hoppers. The North Fork above the reservoir along the road to Yellowstone's east entrance is a freestone with cutthroat. The Bighorn in Wyoming, gauged below Thermopolis, is a big warm river through the Bighorn Basin that becomes the famous tailwater only after it crosses into Montana.
Before you go
Wyoming's rules differ between the state, Yellowstone and Grand Teton national parks, and the Wind River Reservation; the Wyoming Game and Fish Department covers everything outside the parks and the reservation. Runoff timing decides the season: watch the Snake, New Fork and Lamar gauges through June. See the Wyoming fishing hub for every gauged water in the state and the Wyoming trout page for trout detail.