LAKE POWELL, AZ (ARIZONA HIGHWAYS TV) - Lake Powell is the second largest man-made lake in the United States. Lake Mead holds more water, but it's not as big geographically as Lake Powell.
The lake was created by the Glen Canyon Dam in 1966. It backed up 186 miles of the Colorado River, which filled up 96 canyons, creating nearly 2,000 miles of coastline. That's more than the west coast of the United States.
While visiting Lake Powell, consider taking a boat tour to Antelope Canyon. It's an 8-mile tour that gives you a glimpse of how 200 million years of flash floods turned what was once desert into sculpted, sheer high-rises of Navajo sandstone.
During the tour, you'll see holes in the sandstone walls. They were there long before the dam filled the canyon with water. The holes were once filled with organic material and over time, the flash floods exposed them and washed them away.