What is the Grand Canyon?
The Grand Canyon is a huge, steep-sided gorge carved by the Colorado River in Arizona. It is about 446 kilometers long, up to 29 kilometers wide and more than 1.8 kilometers deep.
The Colorado River began cutting the canyon about 5 to 6 million years ago, while the land around it slowly rose. Wind, rain and ice widened it over time. The canyon walls reveal layers of rock that record nearly two billion years of Earth's history, making it a famous site for geologists.
Grand Canyon National Park was established in 1919, and it became a UNESCO World Heritage Site in 1979. It attracts about five million visitors a year. Most visit the South Rim, which is open all year. The North Rim is higher and more remote, closing in winter because of snow.
Exploring the canyon
Visitors can hike trails like Bright Angel into the canyon, ride mules or raft the Colorado River. Several Native American tribes, including the Havasupai, Hualapai and Navajo, have deep connections to the canyon. The Hualapai Tribe operates the Skywalk, a glass bridge over the canyon's edge.
Did You Know?
Temperatures at the bottom of the Grand Canyon can be more than 10 degrees Celsius hotter than at the rim, because of the difference in elevation.