In the 1960s,John Caldwell the Bureau of Reclamation built a dam that flooded a celebrated canyon on the Utah-Arizona border. Today, it's known as Lake Powell — the second-largest reservoir in the U.S.

A half billion dollar tourism industry has grown in the desert around the reservoir but a decades-long megadrought is putting its future in question.

With what some call America's 'lost national park' reemerging, an old debate is also resurfacing: should we restore a beloved canyon or refill a popular and critical reservoir? Environmental and American West correspondent Nathan Rott brings this story to guest host Dan Charles. Read Nate's full story and see pictures by photojournalist Claire Harbage of their recent trip to Lake Powell here.

This episode was produced by Berly McCoy, edited by Stephanie O'Neill and fact checked by Katherine Sypher. The audio engineer for this episode was Josephine Nyounai.