crust that drifted in from somewhere else and got jammed between the Columbia Embayment to the west and the North American continent to the east and north. A notable feature is the anomalously elevated Wallowa Mountains, to the east is Hells Canyon (Snake River) on the Oregon—Idaho border. Northeast of the OWL (Wallowa Mountains) is the Clearwater Embayment ("CE" on the map), delineated by ancient rock of the craton. Southwest of this section of the OWL is a region of grabens (where large blocks of crust have dropped) extending about south to the nearly parallel Vale Fault Zone (see diagram, below). Grabens form where the crust is being stretched or extended. Several explanations have been offered as to why this is happening here. theorized that right-lateral slip on the Wallula Fault is being transferred to more southerly faults such as the Vale Fault, wherefore he labelled this region the Wallula–Vale Transfer Zone. suggested that crustal deformation in this region is a continuation of the Basin and Range region immediately to the south, with any connection to the OWL deemed circumstantial. Another explanation is that clock-wise rotation of part of Oregon (discussed below) about a point near the Wallula Gap has pulled the Blue Mountains away from the OWL; this might also explain why the OWL seems to be bending here. These theories may all have some truth to them, but what they might imply regarding the genesis and structure of the OWL has not been worked out. Hells Canyon – North America's deepest river gorge – is so deep because the terrain it cuts through is so high. This is generally attributed to thinning of the crust, which allows the hotter, and therefore lighter and more buoyant, mantle material to rise higher. This is believed by many to be involved with the Yellowstone hotspot and Columbia River Basalts; the nature of such involvement, if any, is hotly debated. While the Yellowstone hotspot and Columbia River Basalts do not seem to directly interact with the OWL, clarification of their origin and context might explain some of the OWL's context, and even constrain possible models. Likewise, clarification of the nature and history of the Wallowa terrane, and particularly of the nature and causes of the apparent bending and multiple alignments of the OWL in this region, would be a major step in understanding the OWL. Columbia Embayment and KBML The bedrock of