February marked the beginning of a busy time for Ten Sleep Fish Hatchery. The Wyoming Game and Fish facility, located on the west slope of the Bighorn Mountains, is home to one of only two captive broodstocks of Yellowstone cutthroat trout in the country. And in late winter each year, spawning operations begin.  

Once a week over a two-month time frame, crews sort fish and select 3- and 4-year-olds that are ready to spawn. Eggs are then collected from female fish and milt from male fish. By early spring, approximately 1,100 adult female Yellowstone cutthroat trout will be spawned.

Bart Burningham, superintendent of Ten Sleep Fish Hatchery, said the Yellowstone cutthroat trout broodstock is capable of producing 960,000 “eyed eggs.” The term refers to the developmental stage of a fertilized egg when two characteristic dark spots — the trout’s eyes — are visible. 

“Eyed eggs will be shipped to different hatcheries across the U.S. and to Clarks Fork Hatchery in Wyoming near Clark where fish will be raised and stocked within our state,” Burningham said. 

Once 4-year-old fish are spawned at Ten Sleep hatchery, they are stocked in Big Horn Basin waters. In March and April, these 16- to 20-inch, 2- to 3-pound fish will be stocked in Beck Lake in Cody, Water Plant Pond in Basin and Airport Pond in Worland.