The Grand Canyon in Arizona is a 277-mile-long, mile-deep chasm carved by the Colorado River, exposing 2 billion years of geological history. As a UNESCO World Heritage site and major tourist destination, it offers breathtaking views, hiking, and river rafting. Key attractions include Mather Point, Desert View Watchtower, and the North Rim’s solitude.
Grand Canyon National Park preserves an iconic geologic landscape and resources ranging from 1.8 billion (PreCambrian) year-old igneous and metamorphic rocks to 230 million (Triassic)-year-old sedimentary rocks, 5 million (Pliocene)-year old to recent volcanic deposits, a complex tectonic and erosional history, and unconsolidated surface deposits.
The Colorado River established its course through the canyon approximately 6 million years ago and likely evolved from pre-existing drainages to its current course. Geologic processes, including erosion of tributaries and slopes, emergence of groundwater from springs, and active tectonics continue to shape the canyon today. The geologic record in Grand Canyon is an important scientific chronicle and is largely responsible for its inspirational scenery.
Palentology resources include nearly 350 diverse and globally significant fossil localities ranging from 1.2-billion-year-old stromatolites to Paleozoic trilobites, plants, reptile tracks, and marine invertebrates, and Pleistocene megafauna in caves.
Learn more about geology in Grand Canyon National Park.
Wildlife
Birds: 450 species
Mammals: 91 species
Fish: 18 species, 5 native
Reptiles and Amphibians: 58 species
Invertebrates: 1,443 species, including 292 butterflies and moths
Exotic (non-native) animals: 30 species
Range expanding species (not native to the park but to the region, naturally expanding into the park): Mammals: coatimundi, hog nosed skunk, javleina, elk (North Rim); Birds: California Quail, Zone Tailed hawk
Park Endemic animals, not extirpated: 17 species; 1 mammal, 1 snake, 5 butterflies, 1 pseudoscorpion, and 1 tarantula
Regionally Endemic animals, not extirpated: 5 species; One reptile (Grand Canyon Rattlesnake) and three mammals (Kaibab squirrel, and the Navajo Mexican vole) are known only from the Grand Canyon region. At least nine species of insects are endemic to Grand Canyon, and six fish species (humpback chub, razorback sucker, flannelmouth sucker) are endemic to the Colorado River basin.
Federally Endangered and Threatened Species: California condor, humpback chub, razorback sucker, Southwestern Willow Flycatcher, Ridgway’s rail, Mexican Spotted Owl, yellow-billed cuckoo, and desert tortoise.
Extirpated Species: Grizzly bear, black-footed ferret, gray wolf, jaguar, Bear Valley sandwort, Colorado Pikeminnow, bonytail, roundtail chub, and southwestern river otter.
Human History
The oldest human artifacts found date to the Paleoindian period and are nearly 12,000 years old. Since that time, various cultures have continually used and occupied lands that became the park. Archaeological evidence from the following prehistoric culture groups is found in Grand Canyon National Park: Paleoindian, Archaic, Basketmaker, Ancestral Puebloan (Kayenta and Virgin branches), Cohonina, Cerbat, Pai, and Southern Paiute. Historical-period cultural groups include the Hopi, Navajo, Pai, Southern Paiute, Zuni, and Euro-American.
There are currently 3,391 ancestral sites documented within the park dating to the prehistoric period, representing approximately 7.5% of park lands inventoried. In addition, park records document evidence of historic period use from 1540-1950, including 453 locations with evidence of historic Native American use.
Climate in Grand Canyon National Park is relatively mild. However, low humidity generally allows large temperature differences between day and night. Since precipitation totals are low, year-to-year variations can be large. The passage of a few major storms can have a significant impact on the year’s total.
South Rim
Mean High Temperature (30 year average): 64°F (17.8°C)
Mean Low Temperature (30 year average): 29.5°F (-1.4°C)
Average Annual Precipitation (30 year average): 13.4 inches (34.0 cm)
Total Precipitation in 2024: 10.02 inches (25.4 cm)
North Rim
Mean High Temperature (30 year average): 55°F (12.8°C)
Mean Low Temperature (30 year average): 31.7°F (-0.2°C)
Average Annual Precipitation (30 year average): 24.2 inches (61.5 cm)
Total Precipitation in 2024: 21.96 inches (55.8 cm) (25 days of missing data)
Phantom Ranch
Mean High Temperature (30 year average): 81°F (27.2°C)
Mean Low Temperature (30 year average): 54.2°F (12.3°C)
Average Annual Precipitation (30 year average): 9.6 inches (24 cm)
Total Precipitation in 2024: 6.03 inches (15.3 cm) (7 days of missing data)
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