PLEISTOCENE SUBMERGENCE IN COLUMBIA VALLEY 499 



along the river to the south .... which were carried to their present positions 

 by ice."' He does not say "floating ice" but his own later work showed that 

 no glacial ice ever reached this place, and these bowlders may be listed with 

 the others floated in the Columbia submergence. 



Soap Lake and Adrian, Wash. Erratic bowlders very abundant along 

 the Great Northern Railroad in vicinity of these stations. The railroad here 

 crosses the old Grand Coulee channel of the Columbia, occupied whUe the 

 Okanogan lobe blocked the main valley to the west. Altitude of Soap Lake 

 station is 1,202 ft., of Adrian, 1,234 ft. Whether these bowlders were deposited 

 from bergs in Lake Lewis or were dropped while en route to the lake along the 

 glacial Columbia was not determined. At any rate, they lie close to the 

 entrance of the river into the lake. The Coulee City terminal moraine is 

 distant 20 to 25 mi. by the Grand Coulee route, 15 to 20 mi. in a straight line, 

 and the agency of glacial ice cannot be called upon to explain their presence here. 



Ephrata, Wash. "3.7 mi. south of Ephrata, aluminum tablet in large 

 granite bowlder, 1,283 . 102." Leveled in 1903, by R. A. Farmer and in 1909 by 

 C. H. Semner, of the United States Geological Survey (note taken from 

 Bull. 674, U.S. Geol. Surv.)." This is the highest foreign bowlder ever reported 

 from the bed of Lake Lewis, so far as the writer is aware. 



Winchester, Wash. "Twenty feet south of track, opposite section house, 

 in top of granite bowlder, aluminum tablet stamped 1277 T. 1277.333" 

 (data from Bull. 674, U.S. Geol. Surv.). 



The berg-drifted bowlders in the lower Columbia drainage 

 extend almost, if not quite, from the margin of the Okanogan 

 glacial lobe in central Washington to within fifty miles of the 

 Pacific Ocean. This debris did not come from glaciers on the west 

 side of the Cascade Range, for there are no granite outcrops in the 

 drainage of the Willamette Valley. It did not come from glaciers 

 along the east slope of the same range south of Lake Chelan, for 

 none of the valley glaciers here descended below 1,500 feet A. T. 

 and the submergence did not reach much above 1,250 feet A.T. 

 The Chelan Glacier and the Okanogan Lobe appear to have contrib- 

 uted all the bergs which drifted so widely in this inland sea, and 

 debris which they carried was scattered along 350 miles of the 

 lower Columbia Valley. 



Most of this debris lies close to the upper limits of the sub- 

 mergence. This is due to two causes: (i) the opportunity for 

 stranding in shallow water along the shores, where the bergs were 



■ '"A Geological Reconnaissance in Central Washington," U.S. Geol. Surv., 

 Bull. 108 (1893). 



