Barrier Lake, lake in Alberta, Canada

Barrier Lake is a reservoir in the Canadian Rocky Mountains in Alberta. The water is held back by a dam and forms a long, narrow lake nestled between steep mountain walls.

Barrier Lake was created in 1947 by the Calgary Power Company, now TransAlta, to generate hydroelectric power on the Kananaskis River. The dam that impounds the lake stands at its north end. The lake later appeared in the 2003 film X2: X-Men United as a stand-in for Alkali Lake and in the CBC series Heartland as Eagle Lake in 2011.

Highway 40 runs between the lake and Mount Baldy along the eastern shore, where a visitor centre and the Barrier Lake day-use area stand. The dam that holds the reservoir sits at the north end; the Jewell Bay backcountry campground is 4 km from it. Trails circle the lake and become cross-country ski routes in winter.

Barrier Lake stood in for Alkali Lake in the 2003 film X2: X-Men United, and appeared as Eagle Lake in the CBC series Heartland in 2011. The dam holding the water sits at the north end, and the Jewell Bay backcountry campground lies 4 kilometres from it.