Natural wonder North America
Grand Canyon
The Grand Canyon is a giant, deep valley in Arizona, in the United States. A river carved it out of rock. You can see stripes of red, orange and brown rock in its walls.
The Grand Canyon is a huge, steep-sided canyon in Arizona carved by the Colorado River. It is about 447 kilometers long and, on average, 1.6 kilometers deep, and its walls show layers of rock almost two billion years old.
Grand Canyon is a gorge in northern Arizona cut by the Colorado River over the past five to six million years into the uplifted Colorado Plateau. It runs 278 river miles (447 km), averages a mile (1.6 km) deep, and exposes rocks from 1.8 billion years old in the inner gorge up to the 270-million-year-old Kaibab Formation at the rim, a record geologists read layer by layer.
Photo: W. Bulach, CC BY-SA 4.0, via Wikimedia Commons
Discover the Grand Canyon
The Grand Canyon is a very big, very deep valley.
It is in Arizona, in the United States. A river runs along the bottom. The walls have stripes of red, orange and brown rock.
The Grand Canyon is a giant canyon, a valley with very steep sides, in the state of Arizona in the United States. The Colorado River winds along its bottom. Following the river, the canyon is 447 kilometers long, and on average it is about 1.6 kilometers deep, which is a mile straight down.
From one rim to the other it is about 16 kilometers across on average. The South Rim stands about 2,100 meters above sea level and the North Rim about 2,400 meters. Grand Canyon National Park protects it, and it has been a World Heritage Site since 1979.
Grand Canyon National Park covers 4,931 km² (1,218,375 acres) of northern Arizona. The National Park Service gives the canyon's length as 278 river miles (447 km); its rim-to-rim width averages 10 miles (16 km), reaching 18 miles (28.8 km) at most and narrowing to 600 feet (180 m) at Marble Canyon, and its average depth is 1 mile (1.6 km). The South Rim lies at about 7,000 feet (2,100 m) and the North Rim at about 8,000 feet (2,400 m).
The Colorado River, 1,450 miles (2,333 km) long from the Rocky Mountains to the Gulf of California, flows through the canyon with an average width of 300 feet (90 m). Theodore Roosevelt proclaimed Grand Canyon National Monument in 1908; Congress made it a national park on 26 February 1919, and UNESCO inscribed it on the World Heritage List on 26 October 1979.
- Length (river miles)
- 278 miles (447 km)
- Average depth
- 1 mile (1.6 km)
- Average width, rim to rim
- 10 miles (16 km)
- National park since
- 1919 (World Heritage Site, 1979)
How the canyon was carved
First, layers of rock piled up, one on top of another.
Then the land was slowly pushed up high. Then the river began to cut down into the rock. Little side streams made the canyon wider.
Park rangers tell the canyon's story with four steps: Deposition, Uplift, Down cutting and Erosion, or DUDE. First came deposition: layer upon layer of rock formed, starting almost two billion years ago. The top layer, the Kaibab Limestone, formed at the bottom of an ocean.
Next came uplift. Between about 70 and 30 million years ago, the movement of Earth's plates lifted the whole region high and fairly flat, making the Colorado Plateau. Then, starting about five to six million years ago, the Colorado River began cutting downward. Erosion by side streams and of the slopes widened the canyon. The canyon is much younger than the rocks it cuts through.
The National Park Service summarizes the canyon's origin as deposition, uplift, downcutting and erosion. Igneous and metamorphic rocks of the inner gorge formed almost two billion years ago (the NPS gives 1.8 billion years for the oldest rocks); above them lie sedimentary layers up to the Kaibab Formation, 270 million years old, a limestone formed on the sea floor and now found at elevations up to 9,000 feet.
Between 70 and 30 million years ago, plate tectonics lifted the region into the high, relatively flat Colorado Plateau, probably during the Laramide Orogeny, with the rocks raised largely undeformed. How this happened is still investigated; the two favored hypotheses are shallow-angle subduction and continued uplift by isostatic rebound. The Colorado River has been carving downward for five to six million years, and its course through the canyon was established about 6 million years ago. Downcutting needs special conditions; tributary erosion, springs and active tectonics keep shaping the canyon today.
Plants and animals
Many animals live in the Grand Canyon.
There are birds, sheep with curly horns, lizards and snakes. Big birds called condors glide over the cliffs. More than a thousand kinds of plants grow there too.
The canyon is not just bare rock. Park scientists have counted 450 kinds of birds, 91 kinds of mammals, 58 kinds of reptiles and amphibians and 1,737 kinds of plants with roots, stems and leaves.
Bighorn sheep, elk and mountain lions live in the park. The California condor, an endangered bird, can be seen soaring here. In 1982, only 22 condors were left in the wild, so people moved the last ones into zoos to save them. Some animals, such as the Kaibab squirrel, are found only in the Grand Canyon region.
The park's species lists, kept by the National Park Service, include 450 bird species, 91 mammals, 58 reptiles and amphibians, 18 fish (5 of them native) and 1,443 invertebrates, among them 292 butterflies and moths, plus 1,737 vascular plants, 167 fungi, 64 mosses and 195 lichens. Seventeen animal species and 32 plant species are endemic to the park; the Grand Canyon rattlesnake and the Kaibab squirrel are known only from the Grand Canyon region.
Federally endangered and threatened species include the California condor, humpback chub, razorback sucker, southwestern willow flycatcher, Ridgway's rail, Mexican spotted owl, yellow-billed cuckoo and desert tortoise. Some species have been lost from the park, including the grizzly bear, gray wolf and jaguar. Condors fell to 22 wild birds in 1982, and to prevent extinction the remaining birds were placed in zoos; the NPS lists lead from eating contaminated carcasses, power lines, poisoned carcasses and habitat loss as continuing threats.
People and the canyon
People have lived in and around the canyon for a very long time.
Today, 11 Native American tribes have a deep connection to it. They work with the park to look after it.
People have used the land of the Grand Canyon for about 12,000 years. Archaeologists have found objects that old, and remains from many later cultures, including the Ancestral Puebloans.
Today the canyon is home to 11 federally recognized Native American tribes, who have a deep history and connection to it. Tribal governments work with the park on many projects, such as the Desert View Watchtower Intertribal Cultural Heritage Site.
The oldest human artifacts found in the park date to the Paleoindian period and are nearly 12,000 years old. Since then, the NPS notes, various cultures have continually used and occupied these lands; archaeological evidence includes Paleoindian, Archaic, Basketmaker, Ancestral Puebloan (Kayenta and Virgin branches) and Cohonina remains, among others.
The park recognizes 11 federally recognized Tribes with a deep history and connection to the canyon. Tribal governments and communities work with park managers on many programs, including the Desert View Watchtower Intertribal Cultural Heritage Site. The canyon became a national monument in 1908, a national park in 1919 and a World Heritage Site in 1979; UNESCO notes prehistoric traces of human adaptation to a particularly harsh environment.
Visiting safely
Stay on the paths and stay away from the edge.
Hold a grown-up's hand near the rim. Never throw anything into the canyon. Watch animals from far away, and never feed them. Drink lots of water.
The park asks visitors to stay on trails and walkways and to keep at least 2 meters (six feet) back from the edge. Where there is a railing, do not climb over it. Never throw rocks, coins or trash over the edge: they can hurt hikers or animals below, or start a landslide.
Watch wildlife from a distance: stay at least 30 meters (about two bus lengths) from elk, deer, bighorn sheep, condors and mountain lions, and 15 meters from squirrels, birds and lizards. Feeding animals is not allowed. Summer heat deep in the canyon can top 43 °C (110 °F), so rangers say to avoid hiking between 10 a.m. and 4 p.m., carry water and eat salty snacks.
Grand Canyon's safety guidance asks visitors to stay on designated trails and walkways, keep at least six feet (2 m) from the edge, never climb over railings, and never throw anything over the rim, since objects can injure people and wildlife below or start landslides. Wildlife rules call for at least 100 feet (30 m) from elk, deer, bighorn sheep, California condors and mountain lions, and 50 feet (15 m) from smaller animals; feeding animals is prohibited.
The rims sit at 7,000 to 8,000 feet, and the dry climate and altitude can bring sunburn, dehydration and exhaustion. Inner-canyon summer temperatures can exceed 110 °F (43 °C), and trails such as the South Kaibab have no water. The NPS strongly discourages hiking between 10 a.m. and 4 p.m. in summer, recommends plain water plus electrolytes and salty food, and reminds hikers that rescue may be delayed, so they must be prepared to look after themselves.
Amazing facts
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The canyon is much younger than its rocks.
The river started carving the canyon five to six million years ago, but even the Kaibab, the top layer of its walls, is 270 million years old.
Downcutting began five to six million years ago; the Kaibab Formation at the top is 270 million years old and the oldest rocks are 1.8 billion years old.
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The top rock of the canyon was made under the sea.
The Kaibab Limestone, the top layer, formed at the bottom of an ocean and now sits as high as 9,000 feet.
Kaibab Limestone, deposited on the sea floor, is found at elevations up to 9,000 feet on the Colorado Plateau, lifted high and flat without being strongly deformed.
-
The North Rim is higher than the South Rim.
The North Rim is about 2,400 meters above sea level, about 300 meters higher than the South Rim.
The NPS gives rim elevations of about 8,000 feet (2,400 m) for the North Rim and 7,000 feet (2,100 m) for the South Rim.
-
Some squirrels live only near the Grand Canyon.
The Kaibab squirrel is known only from the Grand Canyon region.
The Grand Canyon rattlesnake and the Kaibab squirrel are among the animals known only from the Grand Canyon region.
Words to know
- canyon
- a deep valley with very steep sides, usually cut by a river
- erosion
- the slow wearing away of rock and soil by water, wind or ice
- plateau
- a large area of high, fairly flat land
- uplift
- the slow raising of a large area of land by forces inside the Earth
- sedimentary rock
- rock made from layers of sand, mud or shells pressed together
- rim
- the top edge of a canyon
Discovery challenge
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Which river carved the Grand Canyon?
Which river carved the Grand Canyon?
Which river has been cutting the Grand Canyon for five to six million years?
- The Mississippi River
- The Colorado River
- The Amazon River
Show the answer
The Colorado River
The Colorado River carved the canyon.
The Colorado River cut down into the rock, and side streams widened the canyon.
The Colorado River began downcutting five to six million years ago, after the Colorado Plateau had been uplifted.
-
Which is older: the canyon or its rocks?
Which is older: the Grand Canyon itself, or the rocks in its walls?
How does the age of the canyon compare with the age of the rocks it exposes?
- The rocks are much older
- The canyon is much older
- They are the same age
Show the answer
The rocks are much older
The rocks are much older than the canyon.
The rocks are 270 million to about two billion years old, but the river started carving only five to six million years ago.
Even the Kaibab Formation at the rim is 270 million years old; downcutting began only five to six million years ago.
-
What happened first, long before the canyon?
In the rangers' word DUDE, what happened during Deposition?
In the NPS sequence deposition, uplift, downcutting, erosion, what does deposition describe?
- Rock layers piling up
- The river cutting down
- The land being lifted
Show the answer
Rock layers piling up
First, layers of rock piled up, one on top of another.
Deposition is when layer upon layer of rock formed, long before the canyon existed.
Deposition laid down the sedimentary stack above the ancient igneous and metamorphic basement.
-
Which big, rare bird flies over the canyon?
Which rare bird, once down to 22 in the wild, soars over the Grand Canyon?
Which endangered bird, down to 22 wild individuals in 1982, still faces lead poisoning at Grand Canyon?
- Penguin
- California condor
- Flamingo
Show the answer
California condor
The California condor flies over the canyon.
In 1982 only 22 California condors were left in the wild; today they soar over the park.
After falling to 22 wild birds in 1982, condors were taken into zoos; lead from contaminated carrion remains a threat.
-
What should you do near the edge of the canyon?
What does the park ask visitors to do near the canyon's edge?
Which of these is a Grand Canyon safety rule?
- Throw a stone in to hear it land
- Stay on the path and away from the edge
- Climb over the railing for a better view
Show the answer
Stay on the path and away from the edge
Stay on the path and keep away from the edge.
Stay on trails, keep at least 2 meters back, and never throw anything: it could hurt someone below.
Stay on designated trails, keep at least six feet from the edge, never climb barriers and never throw objects over the rim.
Nearby places
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Natural wonder
Bryce Canyon National Park
Bryce Canyon National Park, in southern Utah, is not really a canyon. It is a row of giant bowls, called amphitheaters, carved into the edge of a high plateau and filled with colorful rock spires called hoodoos. The park says it has the largest collection of hoodoos in the world. Ice and rain shaped them from rocks first laid down in an ancient lake.
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City
Los Angeles
Los Angeles is the second-biggest city in the United States, spread across a wide plain between the mountains and the Pacific Ocean. Founded in 1781 as a small farming village, it grew into a world center of movies and music. About 3.9 million people lived there in 2020.
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Natural wonder
Yosemite National Park
Yosemite National Park lies in California's Sierra Nevada mountains. Its granite cliffs, rounded domes and tall waterfalls were shaped by rivers and then by glaciers, which turned narrow canyons into wide U-shaped valleys. It is also home to giant sequoia trees and hundreds of black bears.
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Natural wonder
Rocky Mountains
The Rocky Mountains, or Rockies, stretch about 4,800 kilometers from northern Canada to New Mexico in the United States. They include more than 100 separate ranges, and their highest peak, Mount Elbert in Colorado, is 4,399 meters tall. Glaciers carved their peaks and valleys, and famous parks such as Banff, Jasper and Yellowstone protect their lakes, hot springs and wildlife.
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City
San Francisco
San Francisco sits on the tip of a peninsula between the Pacific Ocean and San Francisco Bay in California. Spanish settlers arrived in 1776, the Gold Rush that began in 1848 turned it into a booming port, and today it is famous for the Golden Gate Bridge, its cable cars, its steep hills and its summer fog.
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Landmark
Golden Gate Bridge
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Natural wonder
Yellowstone National Park
Yellowstone National Park sits on top of a giant volcano in the western United States. Heat from melted rock deep underground powers more than 10,000 hot springs, geysers, mudpots and steam vents, and the park is home to bison, wolves and two kinds of bears.
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Landmark
Mount Rushmore
Mount Rushmore is a granite mountain in the Black Hills of South Dakota. From 1927 to 1941, nearly 400 workers carved the faces of Presidents Washington, Jefferson, Theodore Roosevelt and Lincoln into it, each about 60 feet (18 meters) tall. Most of the rock was removed with dynamite.
Experiments to try
Explore next
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Watch
Country
United States
The United States is a large country in North America made of 50 states, from icy Alaska to the warm islands of Hawaii. It has the Grand Canyon, the Mississippi River and Yellowstone, and about 342 million people live there.
- Watch Geography Weathering and erosion Weathering is rocks breaking apart where they are: ice in cracks, rain, wind-blown sand and growing roots all do it. Erosion is the next step, when gravity, rain, rivers, waves, wind and glaciers carry the broken pieces away. Over thousands to millions of years, they carve valleys, cliffs and canyons.
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Watch
Animal
California condor
The California condor is the largest wild bird in North America, a giant vulture with wings about 2.8 meters wide. In the 1980s only 22 were left. Thanks to a huge rescue effort, the US Fish and Wildlife Service counted 607 condors at the end of 2025, 392 of them flying free.
- Watch What If? Lab What if a mountain wore away? Even the tallest mountains are slowly broken apart by ice, rain, plant roots and wind, and the pieces are carried away by rivers and glaciers. Imagine following a mountain as it wears away: its rock might end up as sand on a beach, mud on a farm or new land at a river's mouth, while moving plates push other mountains up.
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Watch
Natural wonder
Bryce Canyon National Park
Bryce Canyon National Park, in southern Utah, is not really a canyon. It is a row of giant bowls, called amphitheaters, carved into the edge of a high plateau and filled with colorful rock spires called hoodoos. The park says it has the largest collection of hoodoos in the world. Ice and rain shaped them from rocks first laid down in an ancient lake.
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Natural wonder
Niagara Falls
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Natural wonder
Yellowstone National Park
Yellowstone National Park sits on top of a giant volcano in the western United States. Heat from melted rock deep underground powers more than 10,000 hot springs, geysers, mudpots and steam vents, and the park is home to bison, wolves and two kinds of bears.
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Watch
Natural wonder
Yosemite National Park
Yosemite National Park lies in California's Sierra Nevada mountains. Its granite cliffs, rounded domes and tall waterfalls were shaped by rivers and then by glaciers, which turned narrow canyons into wide U-shaped valleys. It is also home to giant sequoia trees and hundreds of black bears.
For parents & teachers
What children will learn
- Locate the Grand Canyon in Arizona and describe its size.
- Explain the four stages of its formation: deposition, uplift, downcutting and erosion.
- Understand that the rocks are far older than the canyon carved through them.
- Name rim safety and wildlife rules the National Park Service gives visitors.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- How can soft running water cut through hard rock?
- Why do you think the rocks at the top of the canyon are younger than the rocks at the bottom?
- Why might throwing even a small pebble into the canyon be dangerous?
Try at home or in class
- Stack layers of different colored modeling clay, then cut down through them with a butter knife to see the stripes, like canyon walls.
- Make a sand hill in a tray outdoors and pour water slowly from a cup at the top; watch the water carve a little canyon.
Key vocabulary: canyon, erosion, plateau, uplift, sedimentary rock, rim
Where these facts come from
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Natural Earth vector data , Natural Earth (NACIS) (Public domain)
- Park Statistics , U.S. National Park Service, Grand Canyon National Park
- Geology , U.S. National Park Service, Grand Canyon National Park
- California Condor , U.S. National Park Service, Grand Canyon National Park
- Safety , U.S. National Park Service, Grand Canyon National Park
- Hike Smart , U.S. National Park Service, Grand Canyon National Park
- Grand Canyon National Park , UNESCO World Heritage Centre
- Wikimedia Commons , Wikimedia Foundation (Per file (public domain, CC0, CC BY or CC BY-SA); see each media record)
Checked, not yet human-reviewed. Last updated October 24, 2026. Spotted a mistake? Tell us.
Picture credits
- Photo: W. Bulach, CC BY-SA 4.0, via Wikimedia Commons · source · license
- Photo: Jwanamaker, CC BY-SA 3.0, via Wikimedia Commons · source · license
- Photo: Thomas Wolf, CC BY-SA 3.0, via Wikimedia Commons · source · license
- Photo: Stacy from San Diego, CC BY 2.0, via Wikimedia Commons · source · license