Ballard State Forest is a state forest of New Hampshire located in Derry, Rockingham County, in the southeast part of the state. The area of the park is 71 acres (0.29 km2). It includes the Taylor Mill Historic Site, an old sawmill, and Ballard Pond, which provides water for the mill. The forest is located on Island Pond Road, east of the downtown of Derry. The pond drains via Taylor Brook and Island Pond into the Spicket River, a tributary of the Merrimack River.