Here is a really neat relief image* of the Portland/Vancouver basin:
(North is at the top; the lower Willamette River through Portland flows from the lower center to the left center of the image, where it drains into the lower Columbia River, flowing east to west (right to left).)
This image shows well the results of the deep geologic history of this area, including the Missoula Floods.
This deep geologic history has played an important role in Willamette River pollution and pollution abatement efforts. My book on the topic will articulate this dynamic in more detail.
* Many thanks to Sharon Wood Wortman for sending me this image via email a few days ago.