The Historic Site encompasses 2,735 acres (11 km²). In 2002, it received 49,950 visitors. It was authorized as a National Historic Site on April 2, 1957 under nonfederal ownsership. It was authorized for federal ownership and administration by an act of Congress on July 30, 1965.
In 1978, a general master plan for the site was adopted which included the goal of maintaining the site's scenic attributes as closely as possible to its appearance and characteristics present in 1869.