Big Arm

Big Arm State Park encompasses 55 acres on the western shore of Flathead Lake in Lake County, offering stunning lake and mountain views. The park provides camping and lake access on the largest natural freshwater lake in the western United States.

Flathead Lake supports lake trout, bull trout, yellow perch, and whitefish. Bald eagles and ospreys hunt along the lakeshore. Mule deer browse in the surrounding terrain, and migratory waterfowl visit during spring and fall.

Ponderosa pine and Douglas fir grow on the slopes above the lake. Native bunchgrasses and wildflowers cover the drier areas. The lakeshore supports willows and other riparian vegetation, while the park's grounds include both native and landscaped areas.

Flathead Lake was carved by massive glaciers during the Pleistocene ice ages. The lake occupies a glacially scoured basin and covers approximately 191 square miles with a maximum depth of 370 feet. The surrounding Mission Mountains add dramatic alpine scenery.

Flathead Lake moderates the local climate, producing milder winters and cooler summers than surrounding areas. Annual precipitation averages about 15 inches at the lake level. The lake rarely freezes completely.

The Flathead Lake area is the homeland of the Confederated Salish and Kootenai Tribes. Big Arm Bay has been an important gathering and fishing location for Native peoples for thousands of years.

Big Arm State Park was established to provide public access to the western shore of Flathead Lake. The park offers one of the most scenic camping locations on the lake.

Lake access for swimming, boating, and fishing is the primary attraction. The park offers spectacular sunset views over Flathead Lake with the Mission Mountains as a backdrop. Yurt rentals provide unique lodging options.

The park offers 41 campsites including yurts, a boat launch, a swimming area, and day-use facilities. It is located along Highway 93 on the west shore of Flathead Lake, about 14 miles south of Polson.

The park supports Flathead Lake water quality protection efforts. Invasive species management, particularly for aquatic invaders, is a priority to protect the lake's ecosystem.