Scott K. Johnson, "The Scablands: A scarred landscape as strange as fiction", ars technica 10/12/2014:
In 1922, Bretz tried to bring a group of students to the Cascades, but they were unable to make the last leg of the trip. Instead, they used their remaining time to poke around the Scablands near Spokane. The experience hooked him, and Bretz would return every year to further his research.
In the first couple summers, Bretz and his students mapped an impressive amount of territory, carefully surveying elevations and making observations of the many strange landforms they discovered. They made their way through a number of the dry valleys locally known as “coulees.” While these were plainly products of erosion, there were no streams to be seen. The surrounding region is composed of soft, rolling hills of silty soil, but the rocky coulees had been scraped clean of their sedimentary mantle.