at every surface over which they passed. We are very certain that the ice from Jefferson actually met and joined with that from other high peaks that were at the same time areas of snow accumulation from which glaciers emanated. An abundance of evidence is found that the entire Cascade summit from Mt. Jefferson southward for more than one hundred miles was not only entirely ice-covered, but the rocks everywhere along it were so profoundly eroded that we can gain little conception of the amount of rock material thus carried away.'*
The Three Sisters. The Three Sisters* region is that Photo, Scenic America Co., Portland. THE THBEE SISTEBS (From Deschutes Canyon) section of the summit portion of the Cascade range which is located essentially midway between the Columbia river and
