Somewhere between Bullfrog, Utah, and the Hole in the Rock trailhead, I’m following the distant rumbling of a waterfall, echoing between 500-foot walls of Navajo Sandstone. Not far from here is Cathedral in the Desert — a famed grotto in the heart of Glen Canyon. It gives me chills, knowing that this sound hasn’t been heard since 1968. After rounding one last corner of the canyon, there it is: a 60-foot cascade bellowing into a clear pool. Water in the desert is a magical thing. It’s also a complicated thing.