Rising in the mountains north of Butte, the Boulder River is the largest tributary to the Jefferson River downstream of the Beaverhead-Big Hole River confluence, providing a boost of cold water near the midpoint of the Jefferson’s 83-mile length. The Boulder is a high-value coldwater fishery and provides significant agricultural production in Jefferson County. Dam removal will benefit wild trout spawning in the system. Also important for wild trout, the Boulder averages 2°-4°F colder than the Jefferson River in August, providing critical thermal refugia for coldwater species in the summer.  

The project area is north of I-90 near Cardwell, MT. On the Candlestick Ranch, the Shaw Diversion Dam and two smaller diversions deliver water to 233 acres of cropland. An inadequate fish ladder exists on Shaw dam and frequently clogs with debris, making it inaccessible to migrating trout. In addition, the aging infrastructure is getting more difficult to operate and regulate irrigation withdrawal. This project will alleviate infrastructure concerns by removing the diversions and provide an ecological uplift to the Boulder and Jefferson Rivers through stream restoration, water savings, and wetland development, while maintaining agricultural benefits.

The project will remove Shaw Diversion and two smaller diversions and replace them with instream irrigation pumps that will benefit trout and agriculture. Significant data collection occured at the site over the past three years. Planning, engineering, and design for the dam removal and stream restoration is underway. The partners anticipate project implementation in the fall/winter of 2025.

Community Partners

The funding and planning for this project involves the landowner, Golden Sunlight Mine, with complimentary support from Montana Fish, Wildlife & Parks (FWP), Natural Resource Conservation Service (NRCS), the Department of Natural Resource Conservation (DNRC), Trout and Salmon Foundation, the Cross Charitable Foundation and L.R. Huckaba Ranch.

MTU relies on the contributions of local partners and individual donors to make up crucial matching funds for federal, state, and local grant awards. We are seeking to raise an additional $300,000 to reconnect this important area of the Boulder-Jefferson watershed. Your gift can help save wild trout in southwest Montana.