Allamuchy Mountain State Park is located in Allamuchy Township and Byram Township in the Allamuchy Mountain region of New Jersey. The park is operated and maintained by the New Jersey Division of Parks and Forestry. There are more than 20 miles (32 km) of unmarked trails in the northern section of Allamuchy, and 14 miles (23 km) of marked multi-use trails. The park is in the Northeastern coastal forests ecoregion. The 2,440 acres (9.9 km2) of mixed oak and hardwood forests and maintained fields of this natural area display various stages of succession. It is situated on the Musconetcong River.