Heart Lake Trailhead (8N1) is a popular backcountry access point located on the east side of the South Entrance Road, approximately 7 miles south of West Thumb, featuring a parking area, information kiosk, and vault toilet. The moderate 17.

4-mile one-way Heart Lake Trail is closed April 1 through June 30 due to bear activity, and a backcountry permit is required for overnight camping and boating.

The trailhead provides access to Heart Lake, a 2,000-acre backcountry lake suitable for fishing and paddling, with designated campsites along the shoreline and thermal features visible along the descent route.