Bighorn River

The Bighorn is a Wyoming river that becomes a Montana destination at Yellowtail Dam — the 525-ft concrete arch that creates Bighorn Lake. From the Afterbay regulation dam below Yellowtail, the river runs about 13 miles to Two Leggins Bridge through the Crow Indian Reservation. This is the destination water — cold, clear, consistent year-round flows (typically 2,500-4,500 CFS depending on Bureau of Reclamation operations), gravel and weed-bed bottom, and 3,000-5,000 trout per mile. Below Two Leggins the river continues for another 50 miles to the Yellowstone confluence at the town of Bighorn, but warms significantly and the trout fishery thins.

The Bighorn's hatch calendar is short on species but heavy on biomass. Tiny midges hatch year-round; sow bugs (Cleon, freshwater isopods) are present in enormous numbers and form the basis of much of the trout's diet, drifting subsurface in the weed beds. PMDs from late June through July are the river's signature dry-fly event — these are big, slow-water hatches with hundreds of rising fish in the slick water along the inside seams. Tricos from late July through early September give another dry-fly window in the morning. BWOs in fall produce the year's best overcast-day dry-fly fishing. Caddis are present but not dominant. Don't expect salmon flies or golden stones — they're absent. Streamer fishing for big browns picks up in fall and winter, especially in the deeper runs and along the riprap.

The corridor is Fort Smith, MT — a one-stoplight town immediately below Yellowtail Dam. Fort Smith Fly Shop, Bighorn Anglers, and Big Horn River Lodge cluster within a quarter-mile of each other. Drive times: 90 minutes from Billings, 4 hours from Bozeman. The water runs through the Crow Indian Reservation, but the river bed and a 10-foot easement on either side are state navigable water — public access is legal but tribal recreation permits are required to enter reservation land beyond the easement (for camping, eating lunch on a gravel bar, etc.). Boat ramps at Afterbay, Three Mile, Bighorn (the access point not the town), and Two Leggins bracket the float water. The standard floats are Afterbay to Three Mile (3 miles, slow) and Three Mile to Bighorn (6 miles, the most floated stretch). The Bighorn fishes consistently 12 months a year — January can be excellent on midges if afternoon air temps creep above 20°F.