Lake Welch Beach State Park's man-made Lake Welch, with its half-mile-long sandy beach in the wooded hills of the Ramapo Mountains, is the largest beach in Harriman State Park. Originally a small body of water with farmland around the edges, Lake Welch became the large lake that it is today when a dam was completed in 1942. The park offers cool breezes, swimming, fishing, boating, picnicking, hiking and camping in adjacent Beaver Pond Campground. Winter activities include ice fishing and snowmobiling.