Huge areas of dry ground, which would be underwater if the lake was full, at Lake Powell, near Page, Arizona, on May 26, 2015. #

A narrow slot canyon is seen from the air at Lake Powell, near Page, Arizona, on May 26, 2015. #

Gregory Butte is reflected in Lake Powell, near Page, Arizona, on May 25, 2015. #

Sandstone sculpted by water and wind erosion is seen in a slot canyon, one of hundreds that surround Lake Powell, on May 26, 2015. #

A houseboat camps in shallow water in a canyon at Lake Powell on May 26, 2015. #

The Glen Canyon Dam holds back the Colorado River, creating Lake Powell, near Page, Arizona, on May 26, 2015. #

Houseboats are tied up in the marina at Lake Powell on May 26, 2015. #

A powerboat moves through a canyon at Lake Powell on May 26, 2015, with the high-water mark visible above it. #

Dry land exposed by low water levels next to Gregory Butte in Lake Powell on May 26, 2015. #

A powerboat cruises, with Phoebe the dog on the bow, through a cut below Castle Rock in Lake Powell on May 25, 2015. #

Sandstone sculpted by water and wind erosion in a slot canyon near Page, Arizona, on May 26, 2015. #

Huge areas of exposed low-lying ground at Lake Powell on May 26, 2015. #

A boat makes its way around Padre Butte in Lake Powell on May 26, 2015. #

The Glen Canyon Dam holds back the Colorado River near Page, Arizona, on May 26, 2015. #

An area that would be underwater if the lake was full is seen at Lake Powell on May 26, 2015. #

A houseboat is tied up on shore as two jet skis approach below Gunsight Butte in Lake Powell on May 26, 2015. #

A white high-water “bathtub ring” is visible on the shores of Lake Powell on May 26, 2015. #