Press Release
U.S. Fish and Wildlife Service Issues Draft Environmental Assessment for Beaver Dam Notching at Red Rock Lakes National Wildlife Refuge
Media Contacts

LIMA, Mont. — The U.S. Fish and Wildlife Service (Service) has released for public review and comment a draft Environmental Assessment (EA) and Minimum Requirements Analysis Framework for Red Rock Lakes National Wildlife Refuge (Refuge). The proposed action is to improve Arctic grayling access to spawning habitat by notching beaver dams in Red Rock Creek (RRC), some of which are within designated wilderness. 

Arctic grayling (Thymallus arcticus; grayling) are a freshwater species of salmonid that reside in open water in clear, cold, medium to large rivers and lakes. The population that resides in the Upper Missouri River drainage in southwestern Montana is one of four remaining populations of Arctic grayling in the contiguous United States still exhibiting the full spectrum of life history behaviors present in historic grayling populations. RRC, located upstream of Upper Red Rock Lake in the Centennial Valley of southwestern Montana, is the primary spawning stream for the Upper Missouri River Arctic grayling population. However, beaver dams have been documented to partially or entirely block grayling movements in RRC, preventing access to spawning habitat. 

Notching removes a portion of each beaver dam with primitive hand tools to ensure grayling have access to upstream spawning areas. As proposed in the EA, notching beaver dams would occur each spring prior to grayling spawning.  Beavers will typically rebuild these dams over the course of the following summer. No ground disturbance would occur.

The Service appreciates public input to assist refining the draft EA and inform our final decision. A copy of the draft EA can be reviewed on the Refuge website at: Red Rock Lakes National Wildlife Refuge Beaver Dam Notching Draft Environmental Assessment. The Minimum Requirements Analysis Framework can be reviewed at: Arctic Grayling Spawning Access Minimum Requirements Analysis Framework Workbook.                     

A 30-day public comment period for the draft EA will run from February 1 through March 1, 2024. Comments can be submitted by email to: or by mail to: U.S. Fish & Wildlife Service, NWRS Planning Division, P.O. Box 25486 DFC, Denver, CO 80225.

Learn more about Red Rock Lakes National Wildlife Refuge at:

The U.S. Fish and Wildlife Service works with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. For more information, visit, or connect with us through any of these social media channels: FacebookX (formerly known as Twitter), Flickr, and YouTube