A bathtub ring marks the high-water line on Nevada's Lake Mead, which is on the Colorado River, in 2013. Julie Jacobson/AP hide caption

itoggle caption Julie Jacobson/AP

Rowan Jacobsen, in the canoe, and Pete McBride and Sam Walton, on stand-up paddleboards, travel through the upper limitrophe of the delta reach (the section marking the U.S.-Mexico border). Before the dam release, Jacobsen described this parched riverbed as a scene of "Mad Max misery." The temporary flow of water helped bolster native habitats that survive here. Courtesy Fred Phillips hide caption

itoggle caption Courtesy Fred Phillips