Mojave National Preserve is a United States National Preserve located in the Mojave Desert of San Bernardino County, California, USA, between Interstate 15 and Interstate 40. The preserve was established October 31, 1994, with the passage of the California Desert Protection Act by the US Congress, which also established Joshua Tree National Park and Death Valley National Park as National Parks. Previously, some lands contained within the Preserve were the East Mojave National Scenic Area, under the jurisdiction of the Bureau of Land Management. At 1,542,776 acres (6,243 km2), within the contiguous United States it is the third largest unit of the National Park System and the first largest National Preserve. The preserve was created within the Pacific West Region of the National Park Service and remains within that jurisdiction today.