Though the Grand Canyon may receive all the attention due to its tremendous size, the smaller canyons of the Southwest are arguably more sublime. This true-color image of Zion Canyon in southwestern Utah was taken by the Enhanced Thematic Mapper plus aboard the Landsat 7 satellite on October 10, 2001. Zion Canyon is located in the lower half of the image amidst the crisscross pattern of rock formations. The canyon walls, made of red and white sandstone, rise 2,000-3,000 feet from the canyon floor and are peppered with hanging vegetation. Over a period of four million years, the Virgin River cut a path through the western edge of the Colorado Plateau to form the canyon. The river and its tributaries resemble branches across the gray-green landscape in the upper section of the image. They eventually join the canyon, often as spectacular slot canyons only a few feet wide, and exit at the bottom of the image on the way to the Colorado River.

Image by Robert Simmon, based on data provided by the Landsat 7 Science Team and the Arizona Regional Image Archive