What is the Grand Canyon?

The Grand Canyon is a vast canyon carved by the Colorado River in northern Arizona, about 277 miles long, up to 18 miles wide, and as much as 6,000 feet (more than a mile) deep, exposing nearly two billion years of geologic history in its layered rock walls. The canyon is one of the most famous natural landmarks in the world and was made a national monument by President Theodore Roosevelt on January 11, 1908 and a national park by Congress on February 26, 1919, the seventeenth national park established in the country.

The Colorado River carved the canyon over the past five to six million years as the Colorado Plateau was uplifted, with the river slicing downward as the land rose. The exposed rock layers in the canyon include some of the oldest exposed rocks on Earth, dating from the Vishnu Schist at the bottom of the inner gorge (about 1.84 billion years old) up through Precambrian sediments, Paleozoic limestones and sandstones, and culminating in the Kaibab Limestone at the rim (about 270 million years old). Geologists call this exposure the Geologic Column. The canyon walls show 19 distinct rock layers visible to the naked eye and dozens more to specialists.

The Grand Canyon is divided by the Colorado River into the South Rim and the North Rim. The South Rim is more accessible and far more visited, with Grand Canyon Village offering hotels, museums, and viewpoints, and elevation around 7,000 feet. The North Rim is about 1,000 feet higher at around 8,000 feet, more remote, closed in winter by snow, and visited by far fewer people. The two rims are about 10 miles apart by air but require about 215 miles of driving to circumnavigate the canyon. Famous viewpoints include Mather Point, Yavapai Point, Hopi Point, and Desert View on the South Rim, and Bright Angel Point and Cape Royal on the North Rim. The Bright Angel Trail and the South Kaibab Trail descend from the South Rim to the Colorado River, an elevation drop of about 4,500 feet over 7 to 10 miles each way.

About 6 million people visit Grand Canyon National Park each year, making it the second most visited national park after Great Smoky Mountains. Indigenous peoples including the Havasupai, Hualapai, Hopi, Navajo, Paiute, and Zuni have lived in and around the canyon for centuries. The Havasupai still occupy a small reservation in the side canyon of Havasu Creek, famous for its blue-green waterfalls. John Wesley Powell led the first documented descent of the Colorado River through the canyon in 1869. The canyon supports diverse ecosystems from desert at the bottom to ponderosa pine and aspen at the rims.