Zion National Park, of which the Great White Throne is a principal attraction, is one of the principal features of the state of Utah and the Colorado Plateau. The plateau covers an area of more than 50,000 square miles (130,000 square km) and is bounded to the east by the Rocky Mountains and the Rio Grande Valley and on the west by the Great Basin. The Colorado River flows through the plateau. The area is mainly desert. Zion National Park is one of the Utah attractions that brings several million tourists to the state annually.