Nine miles in length and covered by 2,500 acres of freshwater, Lake Hopatcong is the focal point of the park. Hopatcong State Park is at the southwest end of the lake and is a popular spot for fishing, boating, and swimming.
Lake Hopatcong was originally created as part of the Morris Canal, a 90-mile waterway that ran from Newark to Phillipsburg and was the chief means of transporting coal, iron and zinc across New Jersey in the 1860s.
The lake was the canal's major source of water. In 1866, more than 880,000 tons of freight was transported on the canal. However, as the more efficient Morris and Essex Railroad was established, the canal was abandoned.
The historical museum is located in the old Morris Canal locktender's house and offers exhibits on local American Indian history, the Morris Canal and the history of the lake.
Facilities and activities include Lake Hopatcong, The Morris Canal, Lake Musconetcong, swimming, fishing, hunting, picnicking, basketball, playgrounds and play field, boating / canoeing. Winter sports include ice fishing, snowmobiling, ice skating, ice boating, sledding, ice sailing.