Changes in the Fishery
Before the Bighorn River was dammed in the mid-1960's, the fish species found there were quite different from present times. A few catfish and sauger - a fish related to the perch - were native to the Bighorn and were able to survive the river's vagaries.
The problem for the river as a fishery was due to the variations in water level depending on snowmelt and season. In the spring and early summer, the Bighorn laden with melting snow from the Wind River and Bighorn Mountains, was a torrent that filled the canyon wall to wall and flooded the valley downstream. In the late summer, the river dried up and was a mere trickle.
Few fished the Bighorn, and certainly no one traveled any great distance to try their luck for a few stunted catfish or an occasional deprived sauger.
World Class Fishery - Post Dam
After the last bucket of concrete was poured for the construction of the Yellowtail Dam in 1966, the river was transformed. Behind the dam, now stretched a reservoir 71 miles long filled with a wealth of fish species. Walleye, once scarce, now flourish in Bighorn Lake.
Below the dam, the change was even more dramatic. A fishery, matching any in the United States was formed by the damming of the river. No longer able to carry its load of mud toward the Gulf of Mexico, the water emerges from the lake crystal clear. The Rainbow and Brown Trout in the river now attract anglers from all over the United States.
Today the Bighorn just below the dam is the most fished river in Montana. During normal water flow years, trout can average upward of 11,000 per mile. A once muddied stream has truly been transformed into a clear water, world class fishery.