The Palouse: Loess Hills and the World's Most Productive Dryland Wheat

The Palouse hills of southeastern Washington and north-central Idaho look, from any high point, like a frozen sea. The waves are real in a geological sense: they are the preserved forms of windblown loess, a fine-grained sediment deposited over thousands of years after the Missoula Floods receded from the Columbia Basin at the end of the last ice age. The floods scoured the basalt bedrock. The wind brought the fine sediment back, layer by layer, building deposits up to fifty feet deep in places. What grew on top of it, once the dryland farmers arrived, was wheat.

The Palouse is among the most productive dryland wheat regions in the world. No irrigation. No aquifer. Just deep soil and a climate that delivers enough precipitation at precisely the right intervals for winter wheat to grow and be harvested. Washington State University in Pullman has spent more than a century developing varieties and cultivation techniques specifically for these hills, and WSU's wheat research program has influenced dryland farming on multiple continents.

Steptoe Butte rises out of the loess hills like a foreign object, which in geological terms it is. The quartzite formation at its summit predates the surrounding sediment by more than one hundred million years, a remnant of ancient seafloor that the Missoula Floods simply went around rather than eroding. The view from the top of Steptoe Butte on a summer day, when the wheat is heading toward gold, shows the Palouse in its full expression: ridge after ridge of contoured fields curving around the butte without a single straight line in sight.