In the wash

Desert lifts up; desert washes down. A small quake this week beneath our town served as a reminder of why the mountains half a mile from my house are there. Two inches of rain on my neighborhood last weekend? A reminder of why those mountains aren’t taller.

We plat out the desert, grid it with our sections and townships, and each day the desert rises up to shake off those imaginary lines like rotten fishnet off a leviathan. Here the roads are arrow-straight where we could make them that way, running due north-south or east-west, but the desert’s blueprints are all French curve, no straight-edge even on the flattest playas.

The dog can walk more than a mile now, and we have been taking in the patterns of recent desert flooding along a long straight dirt road. Accumulating rain pools in the low spots until the sodden berm collapses; four inches of breach quickly becomes a foot, a meter. The road sprouts gouges, dendritic and nearly fractal, to sprain the ankles of unwary moon-light runners. Downstream the gouge continues, broadens, follows the laziest path toward the bottom.

On the map, the dry washes here are rendered as dashed blue lines, as though each were an uncomplicated watercourse suffering a temporary embarrassment. It occurred to me this morning that that isn’t quite right. Washes aren’t streams, but floodplains with multiple channels, now diverging, now braiding. This morning, in a small wash, I traced three tiny dried streams four inches across, their paths discernable mainly as flattened grasses, that diverged and conjoined at least four times before the dog lost interest in walking upstream. Downhill she chose a new wash, which arced in a gentle swoop down toward the highway though it was carved in a few violent minutes.