page_title: Zion National Park
section_title: Geology
hierarchical_section_title: Zion National Park / Geology
context_page_description: Zion National Park is an American national park located in southwestern Utah near the town of Springdale. A prominent feature of the 229-square-mile park is Zion Canyon, which is 15 miles long and up to 2,640 ft deep. The canyon walls are reddish and tan-colored Navajo Sandstone eroded by the North Fork of the Virgin River. The lowest point in the park is 3,666 ft at Coalpits Wash and the highest peak is 8,726 ft at Horse Ranch Mountain. Located at the junction of the Colorado Plateau, Great Basin, and Mojave Desert regions, the park has a unique geography and a variety of life zones that allow for unusual plant and animal diversity. Numerous plant species as well as 289 species of birds, 75 mammals, and 32 reptiles inhabit the park's four life zones: desert, riparian, woodland, and coniferous forest. Zion National Park includes mountains, canyons, buttes, mesas, monoliths, rivers, slot canyons, and natural arches.
  Human habitation of the area started about 8,000 years ago with small family groups of Native Americans, one of which was the semi-nomadic Basketmaker Anasazi.
context_section_description: The nine known exposed geologic formations in Zion National Park are part of a super-sequence of rock units called the Grand Staircase. Together, these formations represent about 150 million years of mostly Mesozoic-aged sedimentation in that part of North America. The formations exposed in the Zion area were deposited as sediment in very different environments:
  The warm, shallow (sometimes advancing or retreating) sea of the Kaibab and Moenkopi formations;
  Streams, ponds, and lakes of the Chinle, Moenave, and Kayenta formations;
  The vast desert of the Navajo and Temple Cap formations; and
  The dry near-shore environment of the Carmel Formation.
  Uplift affected the entire region, known as the Colorado Plateaus, by slowly raising these formations more than 10,000 feet (3,000 m) higher than where they were deposited. This steepened the stream gradient of the ancestral Virgin and other rivers on the plateau.
  The faster-moving streams took advantage of uplift-created joints in the rocks. Eventually, all Cenozoic-aged formations were removed and gorges were cut into the plateaus. Zion Canyon was cut by the North Fork of the Virgin River in this way. During the later part of this process, lava flows and cinder cones covered parts of the area.
  High water volume in wet seasons does most of the downcutting in the main canyon. These flood events are responsible for transporting most of the 3 million short tons (2.7 million metric tons) of rock and sediment that the Virgin River transports yearly. The Virgin cuts away its canyon faster than its tributaries can cut away their own streambeds, so tributaries end in waterfalls from hanging valleys where they meet the Virgin. The valley between the peaks of the Twin Brothers is a notable example of a hanging valley in the canyon.
caption: The Kolob Canyons are a set of finger canyons cut into the Kolob Plateau
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