Zion National Park is a national park located in the Southwestern United States, near Springdale, Utah. In 1909, President William Howard Taft named the area a National Monument to protect the canyon, under the name of Mukuntuweap National Monument, and in 1918 the park's name was changed to Zion. A prominent feature of the 229-square-mile (590 km2) park is Zion Canyon, which is 15 miles (24 km) long and up to half a mile (800 m) deep, cut through the reddish and tan-colored Navajo Sandstone by the North Fork of the Virgin River. The lowest elevation is 3,666 ft (1,117 m) at Coalpits Wash and the highest elevation is 8,726 ft (2,660 m) at Horse Ranch Mountain. Located at the junction of the Colorado Plateau, Great Basin, and Mojave Desert regions, the park's unique geography and variety of life zones allow for unusual plant and animal diversity. Numerous plant species as well as 289 species of birds, 75 mammals (including 19 species of bat), and 32 reptiles inhabit the park's four life zones: desert, riparian, woodland, and coniferous forest. Human habitation of the area started about 8,000 years ago with small family groups of Native Americans. The park includes mountains, canyons, buttes, mesas, monoliths, rivers, slot canyons, and natural arches.