600 feet. That’s how deep the Missoula Flood waters were over the floor of Grand Coulee in eastern Washington State, just north of where I live. I just got back from a tour of the area that is often called the channeled scablands, because of the massive (we are talking totally, completely unimaginably huge flows of water) channels sliced deep into basalt bedrock. The tour included areas of Eastern Washington affected be the Missoula Floods, and affected by the Cordelleran Ice Sheet during the last glaciation. This was a very fast-paced tour, with half-hour stops every hour or so (meaning we would stop for half an hour, load into our vans and drive for a half-hour, where we would stop for another 30 minutes before loading up and…), for an entire 12-hour day. The image to the left is of one of the first stops on the trip, a gigantic alluvial fan, coming out Lower Grand Coulee, that was formed during the Missoula Floods. The unique thing about this fan was that the “cobbles” that are normally found in such a fan, were a meter or more in size. Imagine the flows required to move bed load like that!
Another stop during the day including an outcrop of basalt about three miles north of the end moraine of the Okanogan Lobe of the Cordelleran Ice Sheet. We were standing in a spot that was under an incredible mass of ice during the peak of glaciation. The basalt outcrop was polished flat like a marble floor from abrasion by rock junk picked up by the ice as it moved.
I’m tired and cold. I took a lot of pictures today. I will post them in a gallery when I have had a little rest and feel better.