About the Project

The Boulder River flows from the mountains north of Butte, Montana. It is a high-value, coldwater tributary to the Jefferson River, providing critical thermal refugia for coldwater species in the height of summer.

On Candlestick Ranch, the channel-spanning Shaw Diversion Dam and smaller Cardwell Diversion, located four miles upstream of the Boulder’s confluence with the mainstem Jefferson, deliver water to more than 200 acres of cropland. The dam’s small fish ladder, however, is frequently clogged by debris, preventing migrating fish from accessing the Boulder’s thermal refugia and spawning habitat. The antiquated Shaw Diversion is vulnerable to failure from high flows and is getting more and more difficult to use for irrigation. Meanwhile, the headgate on the Cardwell Diversion is completely inoperable.

Montana Trout Unlimited has been leading an effort in coordination with Montana Fish, Wildlife & Parks, the Natural Resource Conservation Service, Golden Sunlight Mine, Jefferson County, and a 5th generation rancher to remove the longstanding diversions. The project will replace the diversions with instream irrigation pumps that will benefit aquatic species, agricultural water users, and people recreating on the river.  The partners anticipate construction to begin in 2025. The project will also restore nine acres of stream, riparian, wetland, and upland habitat. This is the first in a suite of projects to improve the overall health of the Boulder River watershed.  Importantly, it also provides a replicable model for working with agriculture to restore river health while maintaining economically important irrigation.