Lake Powell in Glen Canyon, USA37.4N 110.5W
Lake Powell is a huge reservoir on the Colorado River, straddling the border between Utah and Arizona. It is the second largest man-made reservoir in the United States behind Lake Mead, storing 24,322,000 acre feet (3.0001×1010 m3) of water when full.
Lake Powell was created by the flooding of Glen Canyon by the controversial Glen Canyon Dam. Glen Canyon was carved by differential erosion from the Colorado River over an estimated 5 million years. The Colorado Plateau, through which the canyon cuts, arose some 11 million years ago. Within that plateau lie layers of rock from over 300 million years ago to the relatively recent volcanic activity.