If you're hunting for a current bighorn river fishing report thermopolis has plenty of hungry trout waiting for you right now. Whether you're a local or someone planning a trip to this weird and wonderful corner of Wyoming, you probably already know that "The Horn" is one of those legendary tailwaters that rarely lets you down. It's consistent, it's productive, and honestly, it's just a blast to fish when the conditions line up.
Right now, the river is settling into its groove. Since it's a tailwater coming out of the bottom of Boysen Reservoir, we don't have to worry quite as much about the massive runoff blowouts that plague other Wyoming rivers. That said, the flows do fluctuate based on what the Bureau of Reclamation decides to do with the dam, so it's always worth checking the cfs (cubic feet per second) before you hitch up the boat.
What's Biting and How to Catch Them
If you've spent any time on the Bighorn near Thermopolis, you know the deal: it's a nymphing game about 90% of the time. If you're a purist who only throws dry flies, you might have some long afternoons, but if you're willing to stare at a bobber—sorry, indicator—you're going to have a very good day.
The trout here aren't exactly picky, but they are focused. They're dialed in on the basics. Sowbugs and scuds are the bread and butter of this river. If you aren't running a Ray Charles or some variation of a pink or orange scud, you're basically just practicing your casting. The fish are fat, healthy, and they love those little protein morsels that tumble along the bottom.
Lately, we've seen a lot of success with midges, especially in the mornings. A little Zebra Midge or a Manhattan Midge trailing behind a heavier sowbug is a killer combo. When the water is clear, don't be afraid to go a bit smaller on your tippet, but remember, these fish have some shoulders on them. You don't want to get snapped off by a twenty-inch rainbow because you were being too delicate.
Decoding the Water Flows
The flows are everything here. When the water is steady, the fish find their spots and stay there. If the flows are dropping, the fish tend to get a little spooky and head for the deeper slots. If the water is rising, they'll often push toward the banks to grab whatever worms and bugs are being washed out of the dirt.
As of this bighorn river fishing report thermopolis flows are holding pretty steady, which makes for predictable drifts. You'll find the most success in the "Wedding of the Waters" section down to the first few boat ramps. That upper stretch is where the Wind River officially becomes the Bighorn, and the water quality there is usually top-notch. It's oxygenated, cool, and the fish are stacked in the riffles.
When the Dry Fly Action Heats Up
Now, I know I said it's a nymphing river, but there are those magical windows where the surface comes alive. We're coming into that time of year where you might see some Blue Winged Olives (BWOs) popping if you get a nice, overcast day. There's nothing quite like seeing a big brown trout nose break the surface in a slow eddy.
If you see bugs in the air, look for the foam lines. On the Bighorn, the foam is your best friend. It traps the bugs, and the trout know it. A size 18 or 20 BWO pattern, or even a Griffith's Gnat if the midges are thick, can produce some heart-stopping rises. Just make sure your presentation is dead-drifted. These fish see a lot of flies, and they can spot a dragging line from a mile away.
Streamer Fishing for the Aggressive Ones
Sometimes, you just get tired of watching an indicator. I get it. When that happens, it's time to break out the sink tip and a meaty streamer. The Bighorn has some truly massive brown trout that didn't get big by eating tiny midges; they got big by eating other fish.
Colors like olive, black, and white are pretty standard. A Sparkle Minnow is almost always a safe bet here. The key is to find the "froggy" water—the slower stuff near the banks or behind big submerged rocks—and give your streamer some life. You're not just looking for a nibble; you're looking for that aggressive, rod-shaking strike. Even if you don't land a monster, chasing them with streamers is a great way to cover water and see parts of the river you might skip while nymphing.
The Thermopolis Vibe
One of the best things about fishing the Bighorn is the town of Thermopolis itself. It's not your typical "glitzy" fly fishing destination, and that's why I love it. It's a bit gritty, very friendly, and has the world's largest mineral hot springs.
After a long day of standing in cold water or sitting in a drift boat, there is absolutely nothing better than soaking in the hot springs. It'll fix your back and your attitude in about twenty minutes. Plus, the local shops are full of people who actually fish the river every day. They aren't just trying to sell you the most expensive gear; they'll actually tell you what's working and where the fish are holding.
Gear You'll Actually Need
Don't overcomplicate your gear list. For the Bighorn, a 9-foot 5-weight or 6-weight rod is the standard. I usually lean toward a 6-weight just because the wind in Wyoming is a real factor. If you've never fished Wyoming before, let me tell you: the wind doesn't "blow," it "attacks." Having a rod with a little more backbone helps you punch through those gusts and actually put your fly where you want it.
For your leader, a standard 9-foot 4X or 5X is usually fine for nymphing. If you're throwing big streamers, you'll want to beef that up to 0X or 2X so you don't lose your favorite fly on the first strike. And don't forget the split shot. The current on the Horn can be deceivingly fast, and if your bugs aren't getting down to the "lunchroom" (the bottom 12 inches of the water column), you're just giving the fish a show they didn't ask for.
A Note on River Etiquette
The Bighorn is a popular spot, especially on weekends. You're going to see other boats. You're going to see wade fishermen. The best way to keep the vibes good is to give everyone plenty of space. If you see a guy wading a run, don't float your boat right through his casting lane. Give him a wide berth and maybe a friendly wave. We're all out there for the same reason—to escape the real world for a bit and catch some fish.
Final Thoughts on the Current Season
Looking ahead, the fishing should stay solid for the foreseeable future. As long as the dam releases stay consistent, the trout will be happy. We're expecting some good hatches as the weather shifts, and the water temperatures are currently sitting in that "Goldilocks" zone where the fish are active and aggressive.
If you're on the fence about making the drive, just do it. The Bighorn is a special river. It's got a personality all its own, and there's something incredibly satisfying about hooking into a wild Wyoming rainbow while the red cliffs of the canyon tower over you. It's big water, big fish, and big fun.
Check back for the next bighorn river fishing report thermopolis update soon, but in the meantime, get your flies in the water. The fish aren't going to catch themselves! Tight lines, and hopefully, I'll see you out there on the water. Don't forget to grab a burger in town afterward—you'll have earned it.