E S S A Y
STONE, WATER, SUPERSTITION, AND BLOOD NATHANIEL FARRELL BRODIE
D
amon and I were walking to Cape Royal, clearing downed trees before the North Rim of Grand Canyon National Park opened for the season, when a four-foot long, wrist-thick gopher snake, brilliant gold and bright black, drifted across our path. I put down my chainsaw and followed the snake, just shy of grabbing it, parting branches to better peer into the desert mahogany in which it took shelter, chattering all the while to Damon until I looked back and realized that he was gone. I found him at the end of the Cape, leaning against the safety rail, looking into the hazy depths of the Grand Canyon. “What happened to you?” “I’m not supposed to be around snakes.” “Oh.” We looked out at the desert. “Why?” “Because I’m Diné.” Years later, miles off the South Rim of the Canyon, I sat on a chunk of sandstone amidst a strewn field of clean stones, their unblemished surfaces exposed to the elements for the first time in two-hundred-and-seventy-five million years. Above me was the sheer, four-hundred-foot Coconino sandstone cliff from which the slide had originated. I sat there, looking at the cliff, at the slide, wondering how and why it came about, and thinking of Damon shunning the snake.
Nikater
As to the collapse, which had razed a large section of the Tanner Trail, I considered the cliff itself, formed from an ancient aeolian sea of sand. Perhaps the extensive cross-bedding within the boulders of the slide signified that the dunes that formed this particular section of cliff were particularly unstable, and this ancient dune instability eventually led to this collapse. Perhaps a rare instance of rain fell on the surface of these dunes, then the moistened sand hardened, was covered by dry sand, and this unusually ossified sediment layer proved the weak link. Or, broader still, the fall may owe to how the Tanner Fault—which the trail exploits to descend to the Colorado River—weakened the cliffs to the forces of erosion. But all that just set the stage. More relevant are the processes by which the cliff was primed for the final, violent kinetics. There is scarp retreat: when groundwater percolating through the porous sandstone reaches the underlying and impermeable Hermit shale and is sluiced out onto the surface. The
