The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The canyon and adjacent rim are contained within Grand Canyon National Park, the Kaibab National Forest, Grand Canyon-Parashant National Monument, the Hualapai Indian Reservation, the Havasupai Indian Reservation and the Navajo Nation.
President Theodore Roosevelt was a major proponent of the preservation of the Grand Canyon area and visited it on numerous occasions to hunt and enjoy the scenery. For thousands of years, the area has been continuously inhabited by Native Americans, who built settlements within the canyon and its many caves.
The Pueblo people considered the Grand Canyon a holy site, and made pilgrimages to it. The first European known to have viewed the Grand Canyon was Garcia Lopez de Cardenas from Spain, who arrived in 1540.
Most of the 5 million annual visitors to the Grand Canyon arrive at the South Rim and experience its beauty from the many overlooks along the canyon edge. Geologically it is hugely significant because of the thick sequence of ancient rocks that are beautifully preserved and exposed in the walls of the canyon.