Mill creek is the largest subwatershed in the upper yellowstone river subbasin supports a yellowstone cutthroat trout metapopulation in 45 stream miles and is therefore a high conservation priority

This $110,000 Cooperative Agreement awarded by the U.S. Department of the Interior Fish and Wildlife Service (CFDA 15.686 - National Fish Habitat Partnership) supports a multi-faceted project to secure, restore, and maintain Yellowstone cutthroat trout populations in the Mill Creek subwatershed in Montana. The primary goals are to construct a fish barrier to protect 10 miles of headwater streams from invasive rainbow trout, and to restore degraded habitat in a 3-mile meadow reach of Mill Creek. The project is being implemented by the non-profit organization Trout Unlimited, which is collaborating with private, state, and federal partners. Key activities include fish passage improvement, habitat reconstruction, riparian restoration, and biological monitoring to address threats from non-native species and degraded stream conditions. This project is part of the National Fish Habitat Partnership's broader efforts to comprehensively address fish habitat decline and support sustainable aquatic ecosystems across the United States.

Nonnative rainbow trout are rapidly expanding their distribution and abundance in the drainage and threaten YCT core conservation populations in upper mainstem mill creek and its tributaries through hybridization. Channelization in 3 miles of what should be the most productive low gradient YCT habitat on mill creek has resulted in a simplified single thread channel depauperate of pools LWD and spawning gravel rendering IT well below its potential for providing quality YCT spawning and rearing habitat. Private nonprofit state and federal partners are working collaboratively through a multifaceted approach to address these threats with the overall goal of securing restoring and maintaining yellowstone cutthroat trout core and conservation populations in the mill creek subwatershed through construction a fish barrier to protect ten miles of headwater streams and through habitat restoration of the degraded meadow reach.