The Lahontan Cutthroat
About the Lahontan Cutthroat - The Lahontan Cutthroat Trout (Oncorhynchus clarki henshawi) is the largest cutthroat trout species and is the state fish of Nevada. It is one of the 14 recognized subspecies of cutthroat. The present distribution is limited to just a few lakes and streams in and closely surrounding its historic range (Northern Nevada, Southeast Oregon and Northeastern California). Historic records indicate there were at least 11 lakes and up to 600 streams inhabited by Lahontans in 1844—those numbers have been reduced to just five lakes and fewer than 130 rivers and streams. The stream dwelling fish have (typically) a dark olive back and red/yellowish sides.the larger lake-dwelling Lahontans are often more silver. Lahontan cutthroat are stream spawners and have the same basic requirement as other trout. The largest recorded Lahontan trout weighed in at 41 pounds but anecdotal records indicate there may have been fish as large as 60 lbs.
History - The Lahontan cutthroat is native to the drainages of the Truckee River, Humboldt River, Carson River, Walker River, Quinn River and several smaller rivers in the Great Basin of North America. These were tributaries of ancient Lake Lahontan during the ice ages until the lake shrank to remnants such as Pyramid Lake and Walker Lake about 7,000 years ago, although Lake Tahoe—from which the Truckee flows to Pyramid Lake—is still a large mountain lake.
Lahontan cutthroats evolved into a large (up to 1 m or 39 in) and moderately long-lived predator of chub, suckers, and other fish as long as 30 or 40 cm (16 in). The trout was able to remain a predator in the larger remnant lakes where prey fish continued to flourish, but upstream populations were forced to adapt to eating smaller fish and insects. Some experts consider O. c. henshawi in the upper Humboldt River and tributaries to be a separate subspecies, O. clarkii humboldtensis or the Humboldt cutthroat trout, adapted to living in small streams rather than large lakes.
When settlement of the Great Basin began in the early 1800's, the Lahontan cutthroat began its decline to near extinction. During the 19th and early 20th centuries, Lahontan cutthroats were harvested in great numbers (up to 1,000,000 lbs each year from 1860 to 1920) and were shipped to towns and mining camps throughout the Western US. First, a dam in Mason Valley blocked spawning runs from Walker Lake. By 1905, the Derby Dam on the Truckee River below Reno stopped Pyramid Lake's spawning runs. A poorly designed fish ladder washed away in 1907, then badly timed water diversions to farms in the Fallon, Nevada area stranded spawning fish and desiccated eggs below the dam. By 1943, Pyramid Lake's population was extinct. Lake Tahoe's population was extinct by 1930 from competition and inbreeding with introduced rainbow trout , predation by introduced lake trout, and diseases introduced along with these exotic species.