GLACIAL WORK IN WESTERN MOUNTAINS 72-3 



Columbia glaciers just north of their union (lat. 48" i 5' approxi- 

 mately), was about thirty-three miles. - .' . ;■,■ 



In the Pend d'Oreille Valley there was another ice lobe, which 

 extended down the valley to a point three miles southwest of 

 Davis Lake. To the northwest this moraine is believed to con- 

 nect with that of the Colville lobe, north of Old Dominion 

 Mountain, though this connection was not established. The 

 moraine of this lobe crosses the Pend d'Oreille River to the 

 eastward at the great bend of the stream eight or ten miles 

 above Newport. East of the Pend d'Oreille the moraine of the 

 east side of this ice lobe was judged, on the basis of topography, 

 to turn northward. 



Another ice lobe came down the Kootenai Valley, but its 

 southernmost limit was not determined. On the basis of data 

 gathered at other times by Professor Chamberlin and the writer, 

 the ice of the Kootenai Valley is believed to have extended to 

 the southern boundary of Pend d'Oreille Lake. It is possible 

 that the Kootenai lobe connected to the northwestward with the 

 Pend d'Oreille lobe ; but, if so, the connection is well to the 

 north of Bonners Ferry, and probably north of the boundary 

 line. 



It remains to be determined whether the Okanogan, Columbia, 

 Colville, Pend d'Oreille, and Kootenai glaciers were marginal lobes 

 of a single continuous ice sheet, the body of which lay to the north, 

 or whether some of them had separate sources in the mountains. 

 The connection of the second and third of these lobes was estab- 

 lished, and data at hand make the connection of the third and 

 fourth seem probable. The connection of the first with second, 

 and of the fifth with fourth, if such connection exists, is proba- 

 bly near the boundary if not beyond it. In any case, the gla- 

 ciers partially traced out were large — quite beyond the Alpine 

 class. 



A few data concerning glaciation farther east were also 

 gathered. General glaciation did not occur as far south as New- 

 port at the east line of Washington. Above Libb}- (in the 

 Kootenai Valley near the west line of Montana) there was gen- 



