As part of the Desert Protection Bill, Joshua Tree National Monument was elevated to park status on October 31, 1994. The bill also added 234,000 acres. The new park boundary follows natural features and includes complete ecological units such as entire mountain ranges. Previous boundaries divided these ranges along survey lines. The additions provide better resource protection with easier boundary identification and monitoring and important habitat for desert bighorn sheep. Elevations in the park range from a low of 536 feet to a high of 5,814 feet at Quail Mountain.