National Park System comprises 401 areas called "units" covering more than 84 million acres in 49 States, the District of Columbia, American Samoa, Guam, Puerto Rico, Saipan, and the Virgin Islands. These units include national parks, monuments, battlefields, military parks, historical parks, historic sites, lakeshores, recreation areas, scenic rivers and trails, and the White House.
National Park System comprises 401 areas called "units" covering more than 84 million acres in 49 States, the District of Columbia, American Samoa, Guam, Puerto Rico, Saipan, and the Virgin Islands. These units include national parks, monuments, battlefields, military parks, historical parks, historic sites, lakeshores, recreation areas, scenic rivers and trails, and the White House.