Lahontan Cutthroat trout are native to lakes and streams throughout the physiographic Lahontan basin of northern Nevada, eastern California, and southern Oregon [MAP]. Historically, it is estimated that millions of these fish inhabited 334,000 acres of lakes and 3,600 miles of streams. Prior to the 1900s, there were 11 lacustrine (lake-dwelling) populations. Today, Lahontan cutthroat trout exist in only a fraction of their historic range in Nevada and California, Oregon, and Utah [CHARTS].

Fossil evidence suggests that the Lahontan’s originated in the Columbia River basin of internal Washington and Oregon. Their movement to the south was facilitated by glacial lakes as the great western glaciers melted. They fed upon native minnows and grew to large sizes. The record fish was caught in Pyramid Lake, Nevada and weighed 41 pounds!

Lahontan cutthroat trout inhabit lakes and streams and use age-specific habitats and age-specific movement behaviors. Both lacustrine and fluvial forms are subject to unique high-risk extinction factors such as the introduction of non-native species, the reduction and alteration of stream discharge, alteration of stream channels and morphology, degradation of water quality, reduction of lake levels and concentrated chemical components in natural lakes.

Independence and Summit Lakes located in California and Nevada, respectively, support the only remaining reproducing lacustrine form of Lahontan cutthroat trout within the native range of the species. Many of the fluvial Lahontan cutthroat trout populations occupy isolated stream segments of larger river systems.

Lahontan cutthroat trout populations are most protected within a networked population (or metapopulation) that requires the potential for movement within the networked population, the potential for different local populations to experience distinct or semi-distinct environments, and the potential for each population to experience independent dynamics.