Of droughts and dams

When completely filled, Lake Powell's coastline is longer than the West Coast of the mainland United States, its sinuous shape outlining almost 2,000 miles of shore along the Arizona-Utah border. The 21st century has been hard on the nation's second-largest reservoir, though, with the southwestern megadrought leaving it below a quarter of its capacity at times (evidenced by the 'bathtub rings' visible here). Though popular for recreation, Lake Powell—and the Glen Canyon Dam that creates it—is a focus of debate: Many environmental groups say the lake should be drained to restore the Colorado River's natural flow.