The water glows during a couple hours each day between April and October when the sun’s rays shoot down through the 700-foot canyon walls. The paddle to Emerald Cave leaves from Willow Beach on ...

It's only accessible by kayak - but that doesn't stop hundreds of tourists from paddling they way to the Emerald Cave. It's only the Colorado River - just below the Hoover Dam.

Fearlessness, and possibly foolishness, compelled Kenton Grua and a small crew to launch a refurbished dory, a flat-bottomed fishing boat, named Emerald ... of the canyon, to the Grand Wash ...

Kevin Fedarko's magnificent book, "The Emerald Mile: The Epic Story of the Fastest Ride in History Through the Heart of the Grand Canyon," covers a lot of ground -- and water. Its wide-ranging ...