Tully Lake, of Royalston, Massachusetts, is a 1,262-acre (511 ha) reservoir and flood control project constructed by the United States Army Corps of Engineers (USACE) in 1949 for 1.6 million dollars.

As of 2007, the USACE reported that Tully Lake had prevented an estimated $26 million in flood damages.

Tully Lake is open to fishing, small boats, hiking, cross country skiing, mountain biking, picnicking, hunting (in season), and swimming.

The Trustees of Reservations, a non-profit conservation organization, operates a 35 site tent-only camping facility on Tully Lake, open seasonally.

[3] The 22-mile (35 km) Tully Trail, a recreational trail cooperatively managed by the USACE, TTOR, the Commonwealth of Massachusetts, the National Park Service, and the Mount Grace Land Conservation Trust, runs along the northern shore of Tully Lake.