National Park Service
The National Park Service (NPS) is the United States federal agency that manages all National Parks, many National Monuments, and other conservation and historical properties with various title designations. It was created on August 25, 1916 by an act of Congress in order to "conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations." It is a branch of the United States Department of the Interior, which is in turn an arm of the executive branch. The NPS oversees 388 units, of which 57 are designated national parks. Other units are designated national monuments, historical parks, national memorials, historic trails, outdoor recreation areas, wild and scenic rivers, lakeshores, seashores, and battlefields. The U.S. Park Police is a law enforcement division of the National Park Service, with jurisdiction in all NPS sites, primarily utilized in urban sites.