Stillwater State Park is a state park located on in Groton, Vermont. The park is located in Groton State Forest close to the Groton Nature Center, Boulder Beach State Park and Big Deer State Park. The park offers camping, picnicking, and access to water-related activities on Lake Groton. The park was developed in the 1930s by crews of the Civilian Conservation Corps (CCC). It is open to the public between Memorial Day weekend and Columbus Day weekend; fees are charged for day use and camping.