Jericho Mountain State Park (also referred to as Jericho Lake State Park) is located in the White Mountains in Berlin, New Hampshire, United States. The park was created in 2005 with the acquisition by the New Hampshire Division of Forests and Lands of two abutting properties: a 230-acre (0.93 km2) city park centered on Jericho Lake, and a 7,200-acre (29 km2) piece of private property to the south. The city park was established in the 1970s with the construction of Jericho Lake, a flood control reservoir built to regulate the flow of the Dead River through the city center of Berlin, located downstream. The city added a small recreational park adjacent to the lake which included a beach, bath houses, picnic sites with grills, and a shelter that is still used for functions to this day. The large private parcel was acquired by the state park system to provide a location for the first network of all-terrain vehicle (ATV) trails on state land in New Hampshire.