The Columbia Plateau is the vast high desert lands of Eastern Oregon and southwestern Washington. Though the geology supports waterfalls, the amount of water in the area is substantially less than that in the mountains and as such few waterfalls occur here. This region encompasses all land in Oregon east of the Deschutes River and Highway 97.
Though the few waterfalls in the region are scattered fairly evenly across the land, by far the most occur in the Wallowa Mountains in the northeastern corner of the state. The volcanic peaks of the Cascades aside, the Wallowas are the tallest mountains in Oregon and have a substantial glacial history. Though much of the Wallowas fall within wilderness areas and the waterfalls in the range havenâ€™t been documented much, a few of the best waterfalls in Oregon fall within the lake-pocked basins in between the deep valleys of the Wallowas. Other waterfalls in the area can be found in the Strawberry and Ochoco Mountains and scattered among canyons feeding into the John Day and Deschutes Rivers. Few waterfalls occur within the southern watersheds that drain into the Great Basin to the south in Nevada and California.