Sylvan Lake is considered the “Crown Jewel” of Custer State Park in the Black Hills of western South Dakota . The mountain lake sits at the base of Harney Peak , the highest point east of the Rocky Mountains. Hikers can access the trailhead for the three-mile trip to the summit.

Other lake activities include swimming, paddleboating, fishing and picnicking.

Sylvan Lake Lodge overlooks the lake and offers cabins, lodge rooms and a dining room.

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As a note of interest, Sylvan Lake was featured in the 2007 movie “National Treasure: Book of Secrets.” Its location was depicted in the film as immediately behind the four faces of nearby Mount Rushmore National Memorial; however, it is actually five miles away.