The Buffalo River is a paradise for those interested in viewing fish underwater. The brightest and most colorful fish in the mid U. S. can be found in the shallows of the Buffalo River. Approximately, 20 species of colorful darters can be found in shallow and swift habitats known as riffles and runs. These habitats are most frequent in the upper and middle districts of the park. In all, 59 species of fish ranging from the small rainbow darter to the aggressive Smallmouth Bass can be found within the Buffalo River. In the past, the fish community was more diverse and more numerous in the number of species found within the river.
In 1951, with the completion of the Bull Shoals dam, the discharge from the dam established a cold water regime within the White River. This allows some species of trout to access the Buffalo River in the winter months, but movements of many warm water fishes, such as the Channel Catfish, have been restricted. This restriction is due to the inability of some warm water fishes to migrate through the cold waters of the White River into the Buffalo River. Currently, a restoration project for Channel Catfish is underway in the Buffalo River use native stock from surrounding watersheds, and some success is being observed.