Each summer, Jackson fish managers monitor the numbers and health of Snake River cutthroat trout in select tributaries of the Snake River as the fish make their way up them for their annual spawning run. The fish are captured in a trap as they swim upstream. Each fish is measured and inspected for any maladies such as the presence gill lice. This is one of several ways fish managers keep tabs on the health and population trends of fish in the state. This long-term data set dates back to the 1960s.


Releasing a Snake River cutthroat after data collection and inspection. Photos by Mark Gocke, WGFD