This area of southeastern Washington consists of scarred black rock cut by canyons, channels, pools, rock basins, ragged buttes and cliffs. The scablands were carved by the catstrophic flows of the Spokane Flood, which occured about 20,000 years ago at the close of the Great Ice Age. This series of floods left their mark all along their 550-mile course from Montana to the Pacific Ocean. Many of the major features of the Columbia Gorge are the result of these floods as well.
Since the 1970's, photographs taken from spacecraft in orbit show the Channeled Scablands look strikingly similar to channeled regions on Mars.