Grand Canyon National Park Tourists Poster

Grand Canyon National Park in Arizona is one of the world's top natural attractions, attracting about five million visitors each year. Here, a few of those tourists take advantage of one of the many spectacular scenic overlooks. Nearly two billion years of Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,093 feet or 1,857 meters) While the specific geologic processes and timing that formed the Grand Canyon are the subject of debate by geologists, recent evidence suggests that the Colorado River established its course through the canyon at least 17 million years ago. Since that time, the Colorado River continued to erode and form the canyon to its present-day configuration