Rattlesnake Dam

Decaying dam is a barrier to fish passage

About the Project

Rattlesnake Dam, located near Missoula, Montana, was built in 1924 to provide water supply to the City of Missoula. The dam suffered damage in 1998 and ceased to serve any function by 2011. The structure blocks Rattlesnake Creek, a tributary to the Clark Fork River that provides important spawning and rearing habitat for federally listed bull trout and westslope cutthroat trout. Former fishing encampments of the Confederated Salish and Kootenai Tribes evidence a historical abundance of trout at the confluence of Rattlesnake Creek and the Clark Fork River.

Removal of the Rattlesnake Dam in August 2020 reconnects the 26 mile-long main stem Rattlesnake Creek from its headwaters in the Rattlesnake Wilderness to the Clark Fork River in downtown Missoula, opening about 31.5 miles of main stem and tributary habitat which made this dam removal a high priority for Montana Fish, Wildlife and Parks and the U.S. Forest Service. The Confederated Salish and Kootenai Tribes also supported this habitat restoration and climate adaptation project.

Partners working on the project consider the Rattlesnake Dam removal as part of a broader effort to reestablish complete fish passage from the Clark Fork River to the Rattlesnake Wilderness, providing access to spawning and juvenile habitat. Removal of the dam also resolves the City’s liability concerns about the decaying structure.

FACTS AT A GLANCE
Owner: City of Missoula
Size: 10 feet tall, 60 feet wide
Project Cost: $1.1 million
ORF Investment: Design, permitting, outreach, monitoring, citizen science, deconstruction, and analysis of stream mitigation crediting scenarios
Miles Opened: 31.5 miles
Fish: ESA-listed fluvial bull trout, westslope cutthroat trout, mountain whitefish, and sculpin
Status: Dam removed fall 2020


RESOURCES
OUTCOMES
  • Open 31.5 miles of mainstem and tributary habitat
  • Improve access to spawning habitat for federally threatened fluvial bull trout, as well as westslope cutthroat and rainbow trout. Improve access to habitat for brown trout, mountain whitefish and sculpin
  • Support basin-scale fishery restoration efforts in the middle and upper Clark Fork River by providing important spawning and juvenile habitat
  • Eliminate the liability risk of a deteriorating dam
  • Support cultural and fishing practices of the Confederated Salish and Kootenai Tribes, for whom Rattlesnake Creek was an important fishing camp and ceremonial gathering place
  • Create opportunities for future recreational enhancements along the Rattlesnake Creek corridor which is heavily used by bikers, hikers, and anglers

Project Partners

City of Missoula

County of Missoula

Montana Department of Natural Resources and Conservation

Trout Unlimited

Watershed Education Network

University of Montana

Confederated Salish and Kootenai Tribes

U.S. Forest Service