Illustration by Steven Schalla, FlyFishingtheSierra.com, used with permission
As with all cutthroats, check first for the cutthroat slash below the jaw. The Lahontan’s slash is a little less distinct than some cutts, but still unmistakable. The Lahontan generally has a greenish bronze back and a coppery to purplish-pink body.
Across most of its range, if you find a cutthroat, it’s almost certainly a Lahontan. The exceptions are in northeastern Nevada, where the range may overlap with the Yellowstone, and eastern California, where it may overlap with the Pauite. Compared to a Yellowstone Cutthroat, the Lahontan will have a greenish back, and is more lightly spotted. The Yellowstone’s back and body is yellowish brown, silvery, or brassy brown. It will not have white edges on its pelvic or anal fins. Compared to a Paiute Cutthroat, the Lahontan generally has 50-100 body spots whereas the Paiute rarely has more than 5, and its flanks will often show light parr marks, which the Lahontan won’t.