Coleman State Park lies on the shore of Little Diamond Pond in Stewartstown, twelve miles east of Colebrook in New Hampshire's remote north country. The excellent trout fishing in Little Diamond Pond and nearby streams makes this park an excellent location for fishing enthusiasts, as well as hunting enthusiasts. Boat rentals and snowshoe rentals are available. With added ATV camping sites, riders are able to leave their campsite and head right out on the trails. Trails from Coleman State Park connect with the 1000 mile of trails for OHRV riding and Snowmobiling in Coos County.

The campground at Coleman State Park offers 25 campsites, including sites for ATV camping with direct trail access.