Bighorn River

The Bighorn River is Montana's premier tailwater trophy trout fishery. Below Yellowtail Dam in Fort Smith, this river produces rainbow and brown trout that average 16 to 18 inches, with 20-inch-plus fish being a realistic daily expectation for experienced anglers.

The fishable tailwater section extends roughly 13 miles from the dam to the takeout at Bighorn Access. This relatively short stretch packs an incredible density of trout — estimates range from 3,000 to 5,000 fish per mile depending on the section and year.

The Bighorn's character is different from Montana's freestone rivers. The water is wide, smooth, and deceptively deep in places. Much of the fishing is done from drift boats, covering the long runs and weed-lined banks where large trout hold. Wade fishing is productive in certain areas, particularly near the dam and at specific riffle sections.

Hatches on the Bighorn are prolific. The river is famous for its midge hatches that occur year-round and can produce fish-catching conditions even in January. Spring brings Baetis (BWO) hatches that stack up with the midge activity. Summer hatches include PMDs, caddis, and yellow sally stoneflies. The fall Baetis emergence is legendary, with trout rising in pods to spent spinners.

Scud and sowbug patterns fished as nymphs are staples year-round, reflecting the aquatic crustaceans that make up a significant portion of the trout's diet. San Juan Worms are also effective, particularly after rain events that wash terrestrial worms into the river.

The Bighorn fishes exceptionally well in winter when most Montana rivers are too cold. Water temperatures from the dam remain relatively stable, keeping trout active and feeding on midges and scuds throughout the coldest months.