Boulder Beach State Park is a Vermont state park in Groton on the western shore of Lake Groton, within Groton State Forest near the Groton Nature Center, Big Deer State Park, and Stillwater State Park. Focused on day use at the lakeshore, it offers seventy-five shaded picnic sites with tables and hibachis, a two hundred-foot beach and swimming area, and a play area. The park also includes rest rooms with lavatories and flush toilets, three large parking lots, a concession stand, and a cartop boat launch, with canoes, kayaks, and pedal boats available to rent.