Coleman State Park is a public recreation area on Little Diamond Pond in Stewartstown, New Hampshire, in Coös County. Created in 1956 when the state bought the 1,200-acre Camp Diamond property from the Coleman family, it has remained a large outdoor destination for camping, hiking, fishing, ATV riding, and picnicking. Centered on the pond and its surrounding landscape, the park also reflects its high northern setting through the Diamond Pond weather station at 2,200 feet. It also stood out as one of ten New Hampshire state parks in the path of totality for the 2024 solar eclipse, giving this quiet recreation area an unusual astronomical distinction.