Williamstown Lake is located in Grant County on Grassy Creek - 2 miles east of Williamstown. The lake was built in 1955 and opened to fishing in 1957. Williamstown Lake is a public 300 acre recreational lake and water reservoir. Public access is available to residents and visitors to enjoy the lake. Fish species present in Williamstown Lake include largemouth bass, bluegill, white crappie, black crappie, redear sunfish, green sunfish, longear sunfish, channel catfish, black bullhead, yellow bullhead, and redhorse sucker.