Grand Canyon, Extensive canyon system cut by the Colorado River, northwestern Arizona, U.S. Noted for its rock formations and coloration, it is about 0.1–18 mi (0.2–29 km) wide and extends from northern Arizona to Grand Wash Cliffs, near the Nevada border, a distance of about 277 mi (446 km). The deepest section, 56 mi (90 km) long, is within Grand Canyon National Park, which covers the river’s length from Lake Powell to Lake Mead. The surrounding plateau is 6,000–9,000 ft (1,800–2,750 m) above sea level, and the canyon is in places more than 1 mi (1.6 km) deep. The national park, now containing 1,904 sq mi (4,931 sq km), was created in 1919. The former Grand Canyon National Monument, established in 1932, was added, with other lands, in 1975. In 1979 the Grand Canyon was designated a UNESCO World Heritage site.
Grand Canyon Article
Grand Canyon summary
Below is the article summary. For the full article, see Grand Canyon.
Colorado River Summary
Colorado River, major river of North America, rising in the Rocky Mountains of Colorado, U.S., and flowing generally west and south for 1,450 miles (2,330 kilometres) into the Gulf of California in northwestern Mexico. Its drainage basin covers 246,000 square miles (637,000 square kilometres) and
Arizona Summary
Arizona, constituent state of the United States of America. Arizona is the sixth largest state in the country in terms of area. Its population has always been predominantly urban, particularly since the mid-20th century, when urban and suburban areas began growing rapidly at the expense of the
United States Summary
United States, country in North America, a federal republic of 50 states. Besides the 48 conterminous states that occupy the middle latitudes of the continent, the United States includes the state of Alaska, at the northwestern extreme of North America, and the island state of Hawaii, in the
World Heritage site Summary
World Heritage site, any of various areas or objects inscribed on the United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage List. The sites are designated as having “outstanding universal value” under the Convention Concerning the Protection of the World Cultural