Endless Grand Canyon
Photograph by Barry Tessman
The red of cactus blooms pops in a Grand Canyon valley. Cut by the Colorado River over millions of years, the Grand Canyon is considered one of the finest examples of arid-land erosion in the world. The immense canyon is 277 miles (446 kilometers) long and averages 4,000 feet (1,200 meters) deep, but it is only 15 miles (24 kilometers) across at its widest.