The fundamental purpose of the National Park Service is to conserve the scenery and the natural and historic objects and the wildlife 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. To accomplish this mission, the National Park Service has employed two law enforcement resources - National Park Service protection park rangers and United States Park Police officers. Although each law enforcement entity functions independently, with distinct day to day tasks, they work cooperatively to accomplish the broad objectives of the National Park Service mission. ....The United States Park Police provide law enforcement service with a particularly urban expertise in National Park Service areas within Washington DC, San Francisco, California and New York City. Park rangers and special agents provide the criminal enforcement and much of the civil enforcement in the remainder of the NPS field areas, with emphasis on natural and cultural resource protection. ....usparks.about.com/cs/natlparkjobs/a/workparkserv_2.htm ..