Bighorn River, Montana

Afterbay Dam to Three Mile

The Bighorn's trout water begins at the Afterbay Dam below Yellowtail Dam at Fort Smith, inside Bighorn Canyon National Recreation Area. The Afterbay ramp is where most floats start, and the Afterbay to Three Mile float is the shortest and most crowded on the river. Wading access is good around the ramp and along the upper miles, and this is the water that fishes easily at lower releases.

Three Mile to Bighorn Access

Three Mile (Lind) fishing access site is the mid-point take-out, and Bighorn FAS, the 13-mile access, is the bottom of the standard float. Nearly all of the river's fame rests on these 13 miles, where the Afterbay smooths out Yellowtail's hydropower fluctuations and irrigation has not yet taken water. Between the state access sites the banks are private or tribal, so wading anglers stay in the river below the high-water mark.

Below Bighorn Access

From Bighorn FAS down through St. Xavier, Mallards Landing and Two Leggins the river slows, warms and picks up irrigation withdrawals. Trout numbers fall off but brown trout become a larger share of the catch and pressure drops sharply. Below Two Leggins the Bighorn is mostly a warmwater river on its way to the Yellowstone near Hardin. Bank access below the 13-mile is almost nonexistent, so this is boat water.

Rainbow trout

Rainbows are the dominant fish in the upper 13 miles, feeding on midges, sowbugs and scuds year-round and rising to baetis in spring and fall, PMDs from mid June, black and tan caddis from July, and tricos on late summer mornings. The Bighorn has no spring caddis hatch; the caddis come after the PMDs.

Brown trout

Browns are numerous through the whole river and become the majority as you move downstream. Fall streamer fishing before the spawn and the November baetis hatch are their season, and the winter months, when the river is nearly empty, are some of the best streamer fishing of the year.

Season and regulations

The Bighorn fishes year-round because dam releases keep it cold, clear and ice-free. Bureau of Reclamation releases set the flow: the upper river wades easily around 1,500 cfs, local guides put the all-around sweet spot at roughly 2,500 to 3,500 cfs, and flows above about 5,000 cfs limit wading to the edges. The 1,500 to 3,500 cfs range is what this page compares the live gauge against.

A Montana fishing license is all that is required to fish the Bighorn inside the Crow Reservation; no tribal permit is needed, a point the FWP regulations state directly. Central District standard limits apply (3 trout daily on rivers, only 1 over 18 inches) and the reach from the cable 600 feet below Afterbay Dam down to Bighorn FAS is artificial lures only. All boats must pass an AIS inspection before launching. Confirm the Central District rules in the current Montana FWP regulations before you launch.