Placid Lake State Park, State park in Missoula County, United States.

Placid Lake State Park covers 31 acres at the eastern end of Placid Lake, 28 miles northeast of Missoula. The park includes the lake's outlet to Owl Creek, a tributary of the Clearwater River. Facilities are a swimming area, campsites, and a boat launch.

The area was named by Hiram Blanchard in 1892, a settler from New York who called it after Lake Placid in the Adirondacks while founding the Clearwater Land and Livestock Company. The region's development was tied to logging and ranching operations that shaped its landscape.

Hiram Blanchard, a New Yorker who came to the area in 1892 to form the Clearwater Land and Livestock Company, named Placid Lake after Lake Placid in the Adirondack Mountains. The name carried over to the state park created in 1977 at the lake's eastern end.

The park lies 28 miles northeast of Missoula at the eastern end of Placid Lake, where the lake drains into Owl Creek. Facilities are a swimming area, campsites and a boat launch; the site covers 31 acres at 1,346 metres. The nearest town is Seeley Lake, about 6 km to the south.

The lake was named by Hiram Blanchard, a New Yorker who arrived in 1892 to form the Clearwater Land and Livestock Company; he borrowed the name from Lake Placid in the Adirondacks. The park itself was created in 1977, five years after a dam was completed below the lake's outlet to Owl Creek.