Collaboration, Commitment, and Adaptive Learning Enable Eradication of Nonnative Trout and Establishment of Native Westslope Cutthroat Trout into One-Hundred Kilometers of Cherry Creek, a Tributary to the Madison River, Montana

A collaborative group of fisheries managers and researchers (Cherry Creek Working Group) took advantage of an 8-m waterfall, 100 km of upstream habitat, and a 3 ha-lake to eradicate nonnative trout and introduce native Westslope Cutthroat Trout (WCT) Oncorhynchus clarkii lewisi in Cherry Creek, a tributary to the Madison River. This project was part of a larger, broad scale effort to restore WCT within the Madison River basin. The project was logistically and politically complex and required long-term commitments by state and federal agencies, a private landowner, nongovernmental partners and university researchers. We describe and discuss the social, legal, and logistical challenges that arose during this project and provide our perspective on why this project succeeded in spite of these challenges. Administrative and legal challenges delayed implementation of the project for several years, but all challenges were resolved in favor of the project's collaborators. Over a 12-year period, nonnative trout occupying the area were eradicated using piscicides, and more than 39,000 WCT eyed eggs and fry were introduced into four geographic areas (phases) that were separated by natural or temporary fish barriers. Population recovery, measured by comparing pre- and post-treatment trout densities and mean sizes, appeared to occur in 3-4 years. We summarize research that documents the effects of piscicides on nontarget species and the expansion of introduced WCT and their progeny to fill all available habitats, along with lessons learned that are helpful to others designing species conservation efforts of similar scale and complexity.