At the headwaters of the Hoosic River, one of the three basins of the 500-acre Cheshire Reservoir, also named Hoosac Lake, stands where the river was dammed in 1866 by the Adams-Cheshire Reservoir Company to provide a consistent water supply for mills downstream. The railroad line built in 1845, now used by the Ashuwillticook Rail Trail, was relocated above the lake's water level. Through the efforts of local citizens, the lake is now publicly owned and managed for its scenic and recreational value, including year-round fishing, boating, kayaking, canoeing, and bird watching. Its shallow depth allows sunlight to reach the bottom, making it vulnerable to explosive weed growth, and non-native aquatic invasive species can spread aggressively, out-competing native species and disrupting the natural ecosystem; cleaning trailers, boat hulls, motors, and fishing equipment helps prevent their spread to other waters.