How Montana Kept Invasive Mussels At Bay This Season

Montana remained free of invasive mussels through the 2025 season, a result credited to the work of Montana Fish, Wildlife and Parks’ Aquatic Invasive Species team, its partners and compliance from watercraft owners stopping at inspection stations.

“In Montana, we are fortunate to have a great group of dedicated staff and partners who work together to prevent invasive species from being introduced to our waters,” said Aquatic Invasive Species Bureau Chief Tom Woolf.

Partnerships were maintained with conservation districts, tribes, city and county governments and nonprofit organizations, including Trout Unlimited and Walleyes Unlimited. Through these partnerships, watercraft inspection stations were operated, early detection surveys were conducted and outreach and education efforts were supported.

During the 2025 season, more than 120,000 watercraft inspections were completed statewide. A total of 38 mussel-fouled watercraft were intercepted, along with 570 vessels transporting aquatic weeds. In addition, more than 20,000 high-risk boats were identified. High-risk vessels were defined as those that last launched in states with known aquatic invasive species infestations. Many of those boats were owned by Montana residents who traveled out of state before returning.

The Clearwater, Ravalli and Anaconda inspection stations recorded the highest traffic, with more than 35,000 inspections conducted collectively. Data indicated that the majority of out-of-state boats originated in Idaho.

“We are also seeing a lot of Montana residents leaving the state, going to mussel-impacted areas and coming home,” Woolf said.

Changes are planned for the 2026 season. For the first time, the High Plains Conservation District will be contracted to operate the Highway 12 watercraft inspection station outside Helena. Work is also underway with the Lincoln Conservation District to identify a new location for the Eureka inspection station.

“Montana is gearing up for another busy season for holding the line against invasive species,” Woolf said.

Inspection stations are scheduled to begin operating in early March, with a focus on snowbird traffic returning from the lower Colorado River area. Inspections remain available by appointment during the winter months by calling 406-444-2440.