The Columbia River Gorge has long been an icon of naturalistic geology. Incised through the Cascade Anticlinorium, the Columbia River supposedly exemplifies the antecedent river hypothesis. This assumes the Cascade Anticlinorium was uplifted at the same rate the Columbia River eroded. In addition to generic challenges to antecedence, it fails to explain planation surfaces along Rowena Gap near the eastern entrance to the Columbia River Gorge. As much as 700 meters above the current river, these planation surfaces truncate folded Columbia River Basalts and extend over 40 kilometers north and south of the Columbia River. Due to their planar nature and no evidence of post-erosion faulting, the planation surfaces were eroded at their current elevation. Secular and post-Flood models alike fail to explain them. That much erosion at such elevation can only be achieved during the Genesis Flood.