Then I came upon a Wall

It's ironic, in this seemingly unending desert, that water creates most of what we see. North of Zion, rain falling on the 11,000-foot-high Colorado Plateau races downhill, slices Zion's relatively soft layers, and pushes its debris off the Plateau's southern edge. This edge is not abrupt, but it STEPS down a series of cliffs and slopes known as the Grand Staircase. Zion's gathered waters, known as the Virgin River, traverse Mojave Desert lands and join the Colorado River in Lake Mead's handmade basin before completing their Pacific-bound journey. At the lowest elevations, Mojave Desert species - desert tortoise and honey mesquite - infiltrate Zion's dry, south-facing canyons. At mid- elevations, Great Basin Desert species like shadscale and big sagebrush mingle with the Colorado Plateau's bigtooth maple and Utah Juniper. Immutable yet ever-changing, these walls were wrought by water. Now, they stand as a silent sentinel to the sands of time. ~Photo taken inside Zion Canyon in September 2007~