The maximum size of a cutthroat trout depends on the species and the environment in which it lives. The most common cutthroat trout species, the Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri), typically reaches a maximum size of 18 to 20 inches, although some individuals may exceed this size. The Lahontan cutthroat trout (Oncorhynchus clarki henshawi) is a subspecies that is found in the Lahontan Basin of the western United States, and it can reach a maximum size of up to 40 inches. The Rio Grande cutthroat trout (Oncorhynchus clarki virginalis) is another subspecies that is native to the Rio Grande basin, and it can reach a maximum size of up to 28 inches.
In general, cutthroat trout are smaller than rainbow trout, and the largest cutthroat trout are typically caught in deep, cold lakes or rivers with abundant food sources. The size of a cutthroat trout is also influenced by a number of factors, including genetics, habitat, and fishing pressure.
