When you think about the Bighorn River, you probably think about the famous stretch of trout water near Fort Smith, Montana. What you may not know is that there is another outstanding tailwater fishery more than 100 miles upstream near the small town of Thermopolis, Wyoming.
Known as one of the many hangouts of Butch Cassidy and his Wild Bunch, the mineral hot springs of Thermopolis make the town a pleasant rest stop for tourists on their way to nearby Yellowstone National Park. The few anglers that do know about the fishing revere it for its solitude, large brown, rainbow, and cutthroat trout, and excellent spring and fall dry-fly fishing.
The Bighorn River officially begins at a place known as the â€śWedding of the Waters.â€ť At this otherwise insignificant spot, the Wind River becomes the Bighorn River. The Lewis and Clark Expedition named the northern (lower) reaches of the river the Bighorn River, while native Americans called the upper reaches the Wind River. Both names seem to have stuck.
The fantastic fishing actually begins on the Wind River below Boysen Reservoir, 15 miles upstream of the Wedding of the Waters. Known as the Wind River Canyon, this scenic stretch of water holds large trout in its deep, bouldery runs. Roadside access is unlimited for anglers with a Wind River Indian Reservation fishing permit.
The terrain changes drastically as the river leaves the 2,000-foot rock walls of the canyon and winds through the red cliffs and farmland on the outskirts of Thermopolis. The river flows north 130 miles to Montanaâ€™s Yellowtail Reservoir, but only Wind River Canyon and the first 20 miles downstream from the Wedding of the Waters, remains cold enough year-round to support trout. This world-class fishery is open all year and offers some of the best dry-fly, streamer, and nymph fishing in the West.
Wyoming landowners can own and control access to the riverbed and anglers cannot wade or anchor a boat on private water. Fortunately, most of the Bighorn River near Thermopolis is owned by the municipality and if you wade out from any public access, you may walk upstream or downstream and fish as long as you stay below the high-water mark. The Wyoming Game and Fish Department has designated several fishing access points and easements over private lands to access the river.
The first one is the boat ramp on Highway 20 at the Wedding of the Waters; several other downstream locations are marked with signs along Highways 20 and 172.
If you are floating, this is a fairly easy river to maneuver with the exception of a few basic rapids and obstacles that can take you by surprise. These include bridge abutments, diversion dams, big boulders, and eroded banks where barbed-wire fence is stretched across bends of the river.
There are three full-day floats near Thermopolis. The first is from the Wedding of the Waters downstream 7 miles to the Eighth Street Bridge boat ramp in Thermopolis. If you want to add another couple of miles to your trip, continue to the Broadway Bridge ramp or a little farther to the Rainbow Terrace boat ramp in Hot Springs State Park. Be aware that in high water, you will not be able to float under a couple of low-hanging bridges downstream of the Eighth Street boat ramp.
The second stretch begins at Rainbow Terrace boat ramp in Hot Springs State Park and ends at the Wakely Farm ramp. This is not a popular float with visitors as you must portage around two diversion dams.
The third stretch begins at the Wakely Farm ramp and goes to the Country Campground or Longwell ramp. If you decide to go farther, you may go on to the Black Mountain Road ramp, 8 miles downstream just off Highway 172.
When to Come
The Bighorn is open year-round and you can catch fish anytime, but some time periods are definitely better than others. The worst times to visit are in the hottest days of late summer when the hatches are sparse and the river is cluttered with weeds, and in midwinter.
The spring and early summer months of March through July have the heaviest hatches and usually provide the best dry-fly action. The pre-runoff fishing in April, before the rainbows get on their spawning beds, can be excellent if you get the right weather and witness the riverâ€™s incredible Baetis hatches. The nymph and streamer fishing is always good when the weeds are absent. The fall fishing turns on again in September and can be great until the bitter cold settles in December. The big browns aggressively chase streamers around spawning time in November, and rainbows can be suckers for egg patterns at this time of year.
Hatches and Tactics
The Bighorn is a prolific midge fishery and these tiny insects hatch every month except August. Early spring and late fall are the best months to witness intense hatches. Trout rarely rise to midge adults on this river, but actively take pupae imitations when adults are on the surface. The Disco Midge, Brassie, WD-40, and RS2 are all great patterns for this hatch.
The first important spring mayfly hatch is the Baetis. Called Blue-winged Olives by most Wyoming anglers, these small (#18-20) insects usually start coming off around the end of March or beginning of April. Overcast, miserable days should provide you with memories of incredible surface action.