The lake trout or mackinaw, Salvelinus namaycush, is popular sport fish native to Alaska, Canada, and parts of the northern United States, including the Great Lakes. The lake trout is not native to Utah, but the species has been introduced to some of Utah's large cold-water lakes, including Flaming Gorge Reservoir, Fish Lake, and Bear Lake. The lake trout can attain a very large size, with fish in Flaming Gorge Reservoir sometimes reaching the fifty pound range.
Adult lake trout prefer to eat fishes, but zooplankton and other invertebrates are consumed when fishes are not available. Lake trout spawn in the fall over areas covered in rocks and gravel. In Flaming Gorge Reservoir, lake trout spawn over the gravel pits that were created when rocks were quarried to build Flaming Gorge Dam. The lake trout is a cold water species, which limits its Utah range to the deep, cold, and calm water of large lakes.