Supplee Lane Recreation Area offers a paved boat ramp with soft launch access on Rocky Gorge Reservoir (T. Howard Duckett Dam) on the Patuxent River, featuring a large paved parking lot with 17 car spaces, 4 handicap spaces, and 32 boat trailer spaces.

The facility includes a picnic area, portable restrooms, and trash receptacles, with access available mid-March through November 30th via a WSSC Watershed Use Permit ($6 daily or $70 annual).

Note: Electric boats and canoes/kayaks only; no gas/diesel motors permitted, and the area was closed as of July 2025 following an oil spill incident.