The Bighorn River You Don't Know
January 01, 2016
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 "Wedding of the Waters." 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 Montana'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 river'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.
Parachute Adams or olive Sparkle Duns work best. The fish are normally not fussy eaters, but sometimes you will see bulges beneath the surface instead of true head-and-tail rises. In these instances, hang a small Pheasant-tail Nymph below your fly or get upstream of the fish and swing a soft-hackle pattern so it rises toward the surface where the fish are feeding.
Most of the dry-fly action on this river is in the slack water near or below a fast riffle or at the tail-out of a slack-water pool. Even on good days the fish will not rise everywhere—they tend to gather in pods in the most productive areas or in "safe zones" along the banks in and around Russian olive roots and branches and other hang-ups.
The largest trout, especially browns, surreptitiously slurp bugs and rarely announce their hiding places. These fish are masters of the invisible rise; all you see is a quick movement of the water and a small ripple. If you find one of these giants and precisely present a fly right in front of its snout, it will usually take it with confidence. Large trout also usually manage to wrap your leader around some obstacle in fairly short order, so it takes luck as well as skill to land these fish.
Green Drakes hatch in late May or early June and are the first large flies of the year, which is nice after squinting to see your #20 fly. Use a #10 or 12 olive Sparkle Dun or Olive Wulff. This hatch is very spotty and while it can produce outstanding fishing at times, it is not dependable.
The fun really starts in late May or early June when early-morning Tricos begin hatching. As soon as it is light enough to see, there are trout rising in a fury. They are so focused on feeding that pulling a few trout out of a pod rarely puts them down.
Male Tricos hatch in the evening just before dark and usually molt into spinners at or before sunrise. Females begin to hatch at sunrise and quickly molt into spinners. Just before the spinner fall takes place in the early morning, there are fogs of Tricos swarming above the riffles. When they begin laying eggs, they can coat the stream surface with their spent, fallen bodies and the trout gorge themselves.
A size 18 or 20 Parachute Adams works well as any fly if you can get it right in front of the fish. Sometimes a bigger or off-color fly actually works better than a realistic imitation because it stands out on the water. Pale Morning Duns (PMDs) begin hatching around the same time of the year as Tricos. When the trout are just finishing the last of the day's spent Tricos, PMDs begin to hatch. Trout quickly switch to these bigger insects, so you need to pay attention. Use a #16-18 Cannon's Bunny Dun or Aire-Flow Cutwing Dun.
Caddis start coming off as early as April but are not a major surface target until June, when a regular evening hatch turns the fish on for a late-night snack. A smattering of various caddis species are on the river through the summer and can be imitated with Henryville Specials, Stimulators, Elk-hair Caddis, and Hemingway Caddis #12-16. A Humpy is also a good pattern for the caddis hatch, especially if you have trouble seeing your fly in low-light conditions.
When there are no trout visibly feeding, nymphing is the most productive way to catch fish on the Bighorn. Tim Wade's Northfork Special is one of my favorites, but Pheasant Tails, Prince Nymphs, and a variety of other nymphs with and without bead heads will catch fish. In the spring, use small nymphs (#18-20) to imitate active Baetis nymphs and midges. Later in the summer when PMDs and Green Drakes may be around, use bigger (#12-16) nymphs. San Juan Worms and olive or orange scuds are also good searching patterns.
Egg patterns are most effective in late April and May when the rainbows are spawning. Drift these patterns downstream of gravel riffles and tail-outs and you'll catch some good brown trout and smaller rainbows. If you are on the river during this time of year, please avoid wading through these spawning areas and do not harass spawning fish.
Streamers and swimming-nymph patterns are also effective during nonhatch periods. Damselfly nymphs can catch fish on a slow retrieve on some of the stillwater sections of river.
In the heat of the summer I like to dead-drift a black bead-head Woolly Bugger with a San Juan Worm dropper. Every once in a while I give it a twitch and get explosive strikes.
Stripping a #6-8 Woolly Bugger, Orange Blossom Special, or a Tequeely is a good idea any time of the year. The best tactic is to cast toward the banks and work the shoreline, especially where there are Russian olive trees or other structure hanging into the river. The only exceptions are when the water temperature is below 45 or above 65 degrees F. and the trout are biding their time in the deep pools. Then I use a fast-sinking or sinking-tip line to get the fly down. When the water is warm, use a heavy tippet and play the fish quickly. Release the trout into well-oxygenated water below a riffle, not into a warm backwater area. If afternoon water temperatures rise above 70 degrees, it may be time for an afternoon siesta.
The river also has sculpins, minnows, crayfish, aquatic worms, and leeches. With the abundant food supply this fishery has to offer, it is no mystery why these trout grow to be pigs!
Terrestrials are a major food item in the summer and especially in the fall months when the water temperature begins to cool. Grasshoppers, beetles, and ants all take fish. Beetle and ant patterns can be hard to see out on the water, so it's not a bad idea to fish a tandem rig with the smaller fly trailing behind a grasshopper. Sometimes the trout will swim up to inspect the hopper and end up inhaling the smaller fly floating nearby.
In the fall the Baetis return. The trout prepare themselves for winter by feeding and gorge themselves when these mayflies make their encore appearance. The brown trout turn golden yellow and become aggressive. This is the best time of year to catch a 26-inch or better brown trout. The cooler water also invigorates the rainbows and cutthroats to the point that they will at times compete for your fly.
In addition to the flies I've mentioned, you'll need two rods for a float trip on the Bighorn. The two most important mayfly hatches here are small insects, and if you want to present a small fly quietly and accurately, you'll need a 3- or 4-weight rod rigged with a 9- to 12-foot leader tapered down to 4X or 5X tippet. I modify the leader depending on the mood of the fish, and sometimes have to go as small as 6X when fishing Tricos. You'll need a bigger 5- to 7-weight rod to pound the banks with streamers or throw a heavy nymph rig. If you were limited to just one rod, a 5-weight would be my choice, but your options will be limited and you will waste fishing time switching from one rig to another and then back again.
Schwalbe's Wyoming Adventures (307-864-2407) is an Orvis-endorsed guide service that specializes in fly-fishing and scenic trips on the Bighorn River as well as pack trips into the Owl Creek Mountains to fish in private streams for native Yellowstone Cutthroat. They also provide shuttle services for do-it-yourself floaters. Bighorn River Outfitters (307-864-5309) also offers fishing trips on the Bighorn, as does Mike Vaughn (307-864-2952).
There are no fly shops in Thermopolis, so come prepared when you visit. Canyon Sporting Goods and Thermopolis Hardware sell licenses and carry a limited selection of fly fishing gear and flies. You can also find licenses at Consumer's Thriftway.
There are many places to stay and many activities for you in Thermopolis. If you are pulling a camper, driving an RV, or want to pitch a tent, several RV parks will take care of you: Country Campin' (800-609-2244), Eagle (307- 864-2416), Fountain of Youth (307-864-3265), Grandview (307-864-3463), Wyoming Waltz (307-864-2778).
Thermopolis has everything from rustic cabins to motels with restaurants, bars, and hot tubs: Cactus Inn (307-864-3155), Moonlighter (307-864-2322), Coachmen (888-864-3854), Elk Antler Inn (307-864-2325), Holiday Inn of the Waters (307-864-3131), Quality Inn (888-919-9009), Rainbow (800-554-8815), Roundtop Mountain (800-584-9126), and Super 8 (307-864-5515).
Wind River Canyon White Water Company (307-864-9343) provides scenic tours of the canyon and is the only outfitter to offer commercial guided fly-fishing trips on the Wind River Indian Reservation. There is also golf, mineral pools, shopping, the Wyoming Dinosaur Center and Dig Site, and the Hot Springs County Historical Museum. Contact the Thermopolis Chamber of Commerce at 1-800-sun-n-spa for more information.
John Schwalbe owns and operates Schwalbe's Wyoming Adventures in Thermopolis, Wyoming.