494 J HARLEN BRETZ 



ancient water body. He believed that they were derived from the 

 Okanogan Lobe of the Cordilleran ice sheet. He found these 

 stranded erratics from the mouth of Wenatchee Valley to the lower 

 portion of Yakima Valley. 



Diller (1895) cited the erratic bowlders of the Willamette 

 Valley as his contribution to the evidences for this Pleistocene sub- 

 mergence. As in Russell's amplification of Symons' idea of a lake, 

 Diller supplied the only trustworthy evidence (and the convincing 

 proof) of the existence of a late Pleistocene water body in the 

 Willamette Valley. Diller, however, thought that the berg-carried 

 bowlders were derived from glaciers descending the western slope 

 of the Cascades. No granite, schist, or quartzite are known to 

 outcrop in this portion of the range, and it is clear that the erratics 

 were carried through the Gorge from regions east of these moun- 

 tains. If Diller was aware of the publications of Symons and of 

 Russell on Lake Lewis, he did not suggest correlation between this 

 lake and Willamette Sound. 



Here, then, is a curious situation with regard to nomenclature. 

 Condon (187 1) has priority of publication, but, so far as we can 

 learn, his conclusion cannot stand on his own presented evidence. 

 It is purely a coincidence that there was such a submergence .as he 

 names. Symons (1882) has a case nearly identical. If Symons 

 had indicated that he found erratic or glaciated bowlders, his case 

 would have been clear. Russell (1893) did not know of Condon's 

 publication, or he would have mentioned it when he admitted that 

 the cause of the ponding was not known. He preferred the hypoth- 

 esis of a glacial dam. It seems unlikely that he did not know of 

 Diller's discovery of granite erratics in the Willamette Valley before 

 his own last-published mention of Lake Lewis (1898). Yet he 

 consistently referred to the ponding as Lake Lewis, clearly not 

 correlating the episode in central Washington with that in western 

 Oregon. Russell and Diller independently discovered the evidence 

 which establishes the existence of the water body under discussion. 

 They are to be credited accordingly, though neither saw as broad a 

 vision as did Condon. 



There was never a glacial dam across the Columbia in the 

 Gorge. The drifted bowlders in Willamette Valley, derived from 



