Cracked takes on the big and complex issue of dams, their impact on rivers worldwide, the weakening rationales for maintaining dams already built or for building more, and how people are working with some success to “crack” these monolithic structures.

Jumping from cliffs at Glen Canyon National Recreation Area in Utah into the cool waters of Lake Powell can be a great activity, if you know exactly what you're jumping into. Is it shallow? Are there submerged objects? There are a number of risky conditions that can arise from jumping into Lake Powell.

Rising water levels have allowed the main boat ramp at the Bullfrog Marina on Lake Powell in Glen Canyon National Recreation Area to open to all vessels. The Bullfrog North Ramp also remains open and available to all boaters. The Bullfrog Main Ramp Spur, adjacent to the eastern side of the main launch ramp, is available for vessels up to 25 feet in length.

You'll soon need a permit if you plan to boat on the Colorado River between the Glen Canyon Dam and Lees Ferry. The National Park Service at Glen Canyon National Recreation Area will begin requiring the free permit on June 1 for that 16-mile stretch of river.