Montana Fly Fishing Forecast 2026: What to Expect on the Bighorn River
The 2026 fly fishing season is shaping up to be a season defined by one overriding concern: water. A warm, dry winter has left the state’s snowpack significantly below normal, and the effects are already being felt on rivers throughout Montana, Wyoming and Colorado. For most freestone rivers across the state, runoff will be lighter and earlier than average, meaning peak spring flows will likely be shorter-lived and low-water summer conditions will arrive ahead of schedule.
The Bighorn River at Fort Smith is a different story — and not entirely a reassuring one. As a tailwater controlled by Yellowtail Dam, the Bighorn is insulated from direct runoff, but it is not immune to drought. Following a warm and dry winter, the Bighorn is facing the prospect of low water levels, with flows potentially dropping below 1,500 cubic feet per second — a threshold that fisheries managers watch closely. Low water levels on the Bighorn doesn’t mean the fishing will be poor — tailwater trout are resilient, and the Bighorn has weathered low-flow years before — but it does mean anglers need to pay attention to flows, be prepared to adjust tactics and expectations, as low flows may increase crowding on the river.
The good news, and there is genuine good news. The Bighorn River has one of the largest reservoirs of any river in the west. The water will run cold and the Bighorn will remain a viable fishing option throughout 2026. The other good news is that the fish themselves are in strong shape. Brown trout and rainbow trout populations in survey areas are doing well, with younger fish showing up in surveys — a positive sign that habitat restoration efforts are paying off. The Bighorn River Alliance, in partnership with Montana Fish, Wildlife & Parks, has spent the past three years dredging side channels that had been cut off from the main river, restoring habitat that benefits juvenile fish survival. The results are showing up in the data. The fish are there. The question is water management. Anne Marie Emery, executive director of the Bighorn River Alliance, has been direct about the concern: rainbow trout spawning beds could be left high and dry if the river drops too low, and the spawning season typically peaks at the end of May. Anglers should pay special attention not to fish over spawning beds to ensure the future of the Bighorn River’s wild trout populations.
Fishing Predictions by Season on the Bighorn:
- Spring still produces some of the most reliable fishing on the Bighorn. Fishing has been very productive so far this year. Trout have been keyed into subsurface food such as sowbug and scuds.Emergences of midges and BWO have been producing great fishing in the afternoons. Streamer fishing on overcast days has been productive.
- We expect the summer season to produce hatches of PMD and Black Caddis. Consistent nymph fishing in riffles and runs will produce the best results for anglers. Summer hatches will bring fish to the surface. Precise presentations will matter more than usual. Fishing early in the mornings and late in the evenings will be advantageous for anglers.
- Fall will bring emergences of Pseudos on overcast days and streamer fishing to pick up as we move into October. Aquatic vegetation growth will be a factor for anglers. The crowds will thin, the cottonwoods will change color and the browns will be dressed in vivid colors of fall.
One important logistical note for 2026: beginning March 1, Montana Fish, Wildlife & Parks no longer allows fly shops to sell fishing licenses. You should purchase your fishing license online before you arrive in Fort Smith.
Fly Fishing the Bighorn in 2026 will demand the anglers attention to conditions, flexibility in timing, and a realistic eye on river conditions. The fish are healthy, the hatches will come, and the river will still fish. Contact the Fly Shop and we can keep you up to date on current conditions and help you plan your fly fishing trip for 2026.
