From fishing to hiking and biking - from lush habitat and rare plants to watching a wealth of wildlife - Moraine Hills State Park is home to a recreational bounty in northeast Illinois. Located 3 miles south of McHenry in McHenry County, the park is located near the Fox River and McHenry Dam, with about half of the park's 2,200 acres composed of wetlands and lakes. In 1939, the State of Illinois made the initial McHenry Dam State Park land acquisition of 15 acres on the east bank of the Fox River. Major acquisition of the Lake Defiance area began in 1971, and construction of park facilities took place in the spring of 1975. The present Moraine Hills State Park opened in October 1976.​ The park name is derived from a geologic formation known as a moraine, which is an accumulation of boulders, stones and other debris deposited by a glacier. The 48-acre Lake Defiance, located near the center of the park, is one of the few glacial lakes in Illinois that has remained largely undeveloped, maintaining a near-natural condition. The waters and wetlands of Moraine Hills are home to abundant wildlife; more than 200 species of birds have been identified at the park. Fishing is available on both Lake Defiance and on the Fox River. The McHenry Dam area provides access to the Fox River, and a fishing pier accessible to visitors with disabilities is available. More than 10 miles of trails make Moraine Hills popular for hikers, skiers and cyclists, and provide one of the park's main recreation features. The concession stand at the McHenry Dam provides refreshments, bait and tackle, and boat rentals for both the Fox River and Lake Defiance. ​