The Bonneville whitefish, Prosopium spilonotus, is one of three whitefish species found only in Bear Lake on the Utah-Idaho border. Bonneville whitefish prefer cold water, and stay in cool deep areas of the lake during the summer months. The species is the focus of limited fishing pressure, primarily during its spawning period.
Bonneville whitefish form large schools and congregate over limited rocky areas in the lake to spawn during November and December. The species eats a variety of aquatic invertebrates, as well as fish eggs and fishes.
Bonneville whitefish obtain larger sizes than Bear Lake whitefish or Bonneville cisco, often growing to over 400 mm in total length. Large Bonneville whitefish are whitish in color, whereas small individuals have dark spots on their backs, making them almost indistinguishable from Bear Lake whitefish. Scale counts are the best way to distinguish the two species.