Alum Creek State Park is a 4,630-acre (1,870 ha) Ohio state park in Delaware County, Ohio, in the United States. Alum Creek Lake was constructed from 1970 to 1974 as part of the Flood Control Act of 1962. Alum Creek Dam was constructed on Alum Creek, a tributary of Big Walnut Creek, which drains into the Scioto River. Alum Creek Reservoir holds 3,387 acres (1,371 ha) of water and is open to fishing, boating, ice fishing, ice boating, and swimming. The park is just north of the state capital of Columbus and contains the remnants of a settlement by freed slaves that arrived in Ohio from North Carolina.