Motorists Hauling Watercraft Must Stop at AIS Inspection Stations

By JOLEEN TADEJ For Montana Fish Wildlife and Parks

Montana Fish, Wildlife & Parks officials remind private and commercial boaters that state law requires all motorists hauling watercraft—from trailers with motorboats or inflatable rafts to canoes and kayaks perched atop cars and pick-up trucks—to stop at inspection stations.

The annual education and enforcement effort, which this year includes multiple chances to win prizes from an array of local sponsors, is to further curb the risk of aquatic invasive species from attaining a foothold in Montana waters.

Seventeen well-marked inspection stations will again be in operation beginning Thursday, May 21 through September at key border crossings, along major highways, and on heavily used water bodies. Motorists who stop will have their equipment checked—and cleaned if needed—and get information on how to enter a raffle for prizes to be awarded throughout the boating season.


Montana law requires private motorists and outfitters and guides hauling watercraft—including motorboats, sailboats, kayaks, canoes, rowboats, rafts, jet skis and even small kick boats popular among some anglers—to always stop at AIS watercraft inspection stations for a brief interview and equipment check. Most inspections take fewer than five minutes but failure to stop could lead to a $135 fine.

Last year, nearly 35,000 watercrafts were inspected at Montana’s roadside stations. A total of 54 motorboats and three non-motorized watercrafts were found to have been fouled by zebra mussels and other AIS contaminants and hundreds more contained standing water or noninvasive vegetation.

“We were able to intercept those boats and clean them up upon inspection,” said Tom Boos, FWP’s AIS coordinator in Helena. “The problem is more than 30 percent of all motorists hauling watercraft aren’t stopping, and some of those boats are likely harboring AIS.”

AIS are non-native, destructive, and highly prolific life forms like harmful aquatic plants, animals, fish, and microscopic organisms, which include everything from invasive zebra mussels to whirling disease.

“They’re mostly transported from water to water by popular recreational activities like boating and angling,” Boos said.

Invasive species’ widespread harm in the U.S. amounts to more than $130 billion in damages and repair each year. For instance, municipal water systems in North Texas, popular recreational lakes in Omaha, Neb., and once healthy fisheries in New York have been shut down or damaged by AIS in recent years. A study shows even property values surrounding nearby lakes in Wisconsin dropped up to 16 percent due to the infestation of invasive, dense, mat-like water weeds.

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While most western states now have mandatory roadside watercraft inspection stations, boaters and others in Montana have been urged for a decade to inspect, clean, drain and dry boats, trailers and gear exposed to the water to self-ensure they don’t carry damaging organisms from one water body to another.

“At the inspection stations, boats and trailers are carefully inspected, and boaters obtain information about how to identify invasive species and prevent their spread from one water body to the next,” Boos said. “And this year, they’ll also get information on how to win some raffle prizes and then be on their way.”

The most likely aquatic invasive species threats to Montana waters include quagga and zebra mussels, Eurasian watermilfoil, and New Zealand mud snails. Montana waters currently infested or treated for AIS include:

  • Eurasian watermilfoil—a willowy plant that forms dense mats of vegetation on the surface of the water and affects recreational activities such as swimming, fishing, water sports and boating—at Beaver Lake, Fort Peck Reservoir, Noxon Rapids Reservoir, Cabinet Gorge Reservoir, Jefferson River, Madison River, the upper Missouri River, Fort Peck Dredge Cuts, and the Missouri River below Fort Peck Reservoir.
  • Curly-leaf pondweed—similar to watermilfoil—that remains on the Bitterroot River, Canyon Ferry Reservoir, Hauser Lake, Holter Lake, Ennis Lake, Hebgen Lake, Missouri River, Clark Fork River, Noxon Rapids Reservoir, Cabinet Gorge Reservoir, Thompson Falls Reservoir, Helena Valley Regulating Reservoir, and Post Creek.
  • Flowering rush—a nearly impenetrably dense high-growing plant that covers lakes and rivers, chokes out native plants and releases bacteria that causes swimmer’s itch—on the Flathead River, Flathead Lake, lower Clark Fork River, Noxon Rapids Reservoir, and Cabinet Gorge Reservoir.
  • New Zealand mud snails—a tiny cone-shaped snail that can quickly grow to densities of up to 30,000 snails per square foot to ruin rivers and lakes by crowding out native species—continue to persist at Darlington Ditch, Hauser Lake, Nelson’s Spring Creek, Bluewater Creek, and on the Missouri River below Holter Dam.

Inspection stations and roving crews will be operating throughout the boating season in these locations: Billings, Bozeman, Clearwater Junction, Culbertson on U.S. Highway 2 West, Dena Mora on I-90 East, Dillon on I-15 North, Eureka on U.S. Highway 37 West, Fort Peck Reservoir, Hardin on I-90, Helena, Missoula, Ravalli on U.S. Highway 93 North, Swan Valley, Thompson Falls, Troy on U.S. Highway 2 East, and Wibaux on I-94 West.

Roving crews will also work at fishing tournaments and other boating events. Raffle sponsors include fishing shops, outfitters, guides and boat manufacturers.

The penalty for knowingly introducing AIS into Montana can be a felony, with penalties up to $5,000 and two years in jail.

For more on AIS, visit FWP’s website at, then click “Aquatic Invasive Species.”