Yellowstone cutthroat trout refuge surveyed near Yellowstone National Park

In 2022, the Greater Yellowstone Coalition worked with a hydrological engineering company to complete an engineering survey for a Yellowstone cutthroat trout restoration project on Crandall Creek, a tributary of the Clarks Fork near Yellowstone National Park. The Crandall Creek watershed offers over 60 miles of refuge for Yellowstone cutthroat trout but is currently threatened by hybridization and competition from non-native trout.

Yellowstone cutthroat trout in a Greater Yellowstone creek. (Photo © Jay Fleming)

Yellowstone cutthroat trout are one of the crucial building blocks in the Greater Yellowstone food web. Countless species such as grizzly bears, river otters, ospreys, and over 50 other bird species rely on Yellowstone cutthroat trout as a source of food. As one of the few truly native trout species in Greater Yellowstone, it’s imperative to conserve their populations and genome for years to come.

However, Yellowstone cutthroat trout face a myriad of issues when it comes to their long-term survival. One of the most pressing threats is the loss of genetic integrity through hybridization with non-native rainbow trout. This hybridization reduces the genetic purity of the native Yellowstone cutthroat trout species. Yellowstone cutthroat trout are also facing increased resource competition from brook trout, another invasive trout species, and this is contributing to a decrease in numbers of Yellowstone cutthroat trout.

GYC Deputy Director of Conservation Charles Drimal examining potential barriers on Crandall Creek.

To help preserve Yellowstone cutthroat trout, the Greater Yellowstone Coalition and Wyoming Game and Fish Department (WGFD) partnered to create a sanctuary for this remarkable trout species. This project requires the creation of an impassable river barrier to non-native trout and the chemical treatment of small stream segments to reduce the high number of rainbow and rainbow-Yellowstone cutthroat hybrids.

In March 2022, I headed out to the field with WGFD to gather data, physically examine potential barriers, and better understand areas where non-native fish could sneak by. We are now waiting on the engineering firm to model two potential barriers and provide recommendations based on the data. Once we receive this report, hopefully by July 2022, GYC and WGFD will determine the next steps in creating this Yellowstone cutthroat trout refuge.

This project was generously funded by many key supporters. A huge thank you to Fly Fishers International, East Yellowstone Chapter Trout Unlimited, Clarks Fork Foundation, Spencer Family Foundation, EcoTrust, Salmon and Trout Foundation, and numerous individual donors for making this Yellowstone cutthroat trout work possible.

—Charles Drimal, Deputy Director of Conservation

The Greater Yellowstone Ecosystem is the land of 49+ Indigenous Tribes who maintain current and ancestral connections to the lands, waters, wildlife, plants, and more.