Which river lies at the base of grand canyon?

The Colorado River lies at the base of the Grand Canyon. The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. It is over 277 miles (446 kilometres) long, up to 18 miles (29 kilometres) wide, and attains a depth of over a mile (6,000 feet or 1,800 metres). The Grand Canyon is one of the most popular tourist destinations in the United States.