National Wildlife Refuge System (NWRS):
Consists of all of the National Wildlife Refuges, the Waterfowl Production Areas, and certain other small tracts managed by states under cooperative agreements with the Fish and Wildlife Service. In general, these areas are managed primarily for conservation of wild plants and animals (particularly waterfowl). Other uses, such as recreation, grazing, energy development, etc., are permitted to the extent they are compatible with the conservation purpose. Some refuges have additional purposes defined in law.