From Flathead Lake—the largest natural freshwater lake west of the Mississippi River—to alpine lakes, free-flowing rivers and legendary blue-ribbon trout streams, Western Montana’s Glacier Country is defined by water. Across the region, boaters, paddlers, anglers, rafters and sailors come to experience recreation surrounded by some of the most scenic landscapes in the country.

Protecting these waterways is a shared responsibility, and one of the most important ways visitors can help is by following Montana’s Aquatic Invasive Species (AIS) laws and prevention measures.

After a day of adventure on the water, practice CLEAN. DRAIN. DRY. to guard against aquatic invasive species.

AQUATIC INVASIVE SPECIES 

Aquatic invasive species (AIS) are non-native plants, animals and pathogens that can cause significant harm to Western Montana’s ecosystems, fisheries and waterways. These species threaten native fish populations, impact wildlife habitat and disrupt recreational opportunities across the state. Invasive species can also damage irrigation systems, clog waterways, affect hydropower infrastructure and create costly long-term environmental challenges.

AIS spreads easily. Watercraft, fishing gear, paddles, nets and waders can unknowingly transport invasive species from one body of water to another. Once introduced, these species are extremely difficult—and expensive—to contain.

Before and after recreating on Montana waters, take these important prevention steps:

CLEAN. DRAIN. DRY.

CLEAN
Remove all mud, plants and debris from watercraft and equipment before leaving the access site.

DRAIN
Drain all water from boats, motors and gear, including live wells and ballast areas.

DRY
Allow watercraft and equipment to dry completely before launching in another waterway.

MANDATORY WATERCRAFT INSPECTIONS

Montana law also requires watercraft inspections prior to launching on state waterways. This requirement applies to more than boats and rafts; kayaks, canoes, paddleboards and river-surfing boards are included as well.

For additional information about inspection stations, boating regulations, fishing licenses and water recreation opportunities, visit Montana Fish, Wildlife & Parks.

Stop at ALL open inspection stations you encounter on your way to the put-in.

Please note: We ask that all our visitors and residents recreate responsibly by being mindful of the following: know before you go; plan ahead; play it safe; leave no trace; tread lightly; and help build an inclusive outdoors.

Updated June 22, 2026

June 17, 2019

Related: Boating, Fishing, Kayaking, Montana, Outdoor Fun, Stand-Up Paddleboarding, Summer Fun, Vacation, Water Fun

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