The Bear Lake Cutthroat Trout

Oncorhynchus clarkii utah

Quick Facts

Common Name: Bear Lake Cutthroat Trout

Scientific Name: Oncorhynchus clarkii utah

Average Size: 24 inches and 5 pounds. The record for the lake is 18 pounds 

Range: Bear Lake in Idaho, Wyoming, and Utah  

Lifespan: They can reach the ripe of age of 15 years

Diet:  They feed primarily on insects and zooplankton when young, switching to fish later. In adults, fish makes up over 95% of their diet

Fun Facts

  • These trout carefully select mates to prevent in-breeding and to give offspring desirable traits like disease resistance. They do this via olfactory and visual clues
  • They can look and focus out of both corners of each eye simultaneously meaning that they can see in almost every direction at once
  • Genetically pure lake strains of Bonneville cutthroat are not believed to be found anywhere within their historic range except Bear Lake
  • They have been introduced into waters like Strawberry Reservoir to control nuisance fish species

Life History

They begin to mature at 5 years of age but may not spawn until 10. Annual spawning occurs during the spring just when the ice has melted. The female lays up to 4000 eggs in the rocky substrate near the shoreline. The newly hatched fry begin to emerge 45-60 days later. In general, growth rates tend to be slower than the river dwelling cutthroat. The young will stick near the shoreline when swimming, using the cover of logs and rocks to avoid predation

The Bear Lake Cutthroat is the lake-dwelling variation of the Bonneville cutthroat and is sometimes called Bluenose Trout. The Bear Lake cutthroat differs from the Bonneville in both biology and ecology. The Bear Lake populations reach a larger size, and have both a longer maximum life span and later age of maturity than the Bonneville populations

The snout and back can be deep azure; its flanks are silvery blue and green with black spots; and its pectoral, pelvic, and anal fins are tinted orange