Click here for interactive river map The Bighorn River is a long and fertile drainage that begins in the high country of Wyoming in the Wind River Range.
The river hits the Montana border near the head of Yellowtail Reservoir. It's that 70-mile reservoir that allows the silt to settle out and the waters to cool by the time they come through Yellowtail Dam into the Afterbay Reservoir.
The trout action begins when the waters come out of the Afterbay Dam, forming a blue-ribbon stretch of trout water that stretches toward Hardin. The most trout-rich stretch is the first 13 miles below the Afterbay, where fish counts have been as high as 10,000 trout to the mile which were seven inches or longer.
The Bighorn is primarily a brown trout river but the rainbows it holds grow big in just a few years. It's that rapid growth of both rainbows and browns, feeding on an insect-rich diet, that makes this a spectacular trout fishery.
