The Black Canyon Water Trail is the stretch of the Colorado River immediately downstream of Hoover Dam — 12 miles of clear, cold water flowing through 240-metre red rock cliffs. Bighorn sheep come down to drink, hot springs steam out of the canyon walls, and the contrast with the parched land above the rim is dramatic.
The river is too cold to swim in at the start but warms as you go. Several outfitters in Boulder City run guided kayak day trips and overnight camping float trips; permits and a launch slot from Hoover Dam are required and limited. The shorter alternative is to put in at Willow Beach further down and paddle upstream as far as the Emerald Cave, a glowing turquoise grotto in the rock.