428 CHARLES A. STEWART 
Lake from the top of this divide to the eastern shore of the lake, 
one sees the eastern line of the ice clearly marked. From this 
shore rises a series of hills with a smoothly rounded topography 
strongly indicating glaciation, but farther in the background is a 
higher ridge of granite, with a serrated and pinnacled outline in 
sharp contrast to the gentler slopes of the lower hills. Closer 
examination of this divide east of Priest Lake valley discloses a 
series of cirques worn out by valley glaciers tributary to the 
International Boundary 
Wray dale 
oF Feit, 
I+ “Land 
Sooke, | 
+ Ss pokane 3 
SE ise d Oreille 
Coulee Ciély Leke 
Coeur 
adAlene 
Fic. 1.—Sketch map of a portion of Idaho and Washington. Crosses indicate 
moraine according to Salisbury. Lined area shows extent of Pend d’Oreille—Priest 
River marginal lobe. 
main ice-sheet. The upper limit of ice in these cirques was about 
7,000 feet.1 The Pend d’Oreille lobe therefore extended eastward 
as indicated by the lined area on the map. 
The basins of Upper and Lower Priest lakes are deep and rock- 
floored, and suggest in all respects a valley scoured and enlarged 
by glaciation, and the lakes themselves can be attributed to no 
other cause than damming by morainal deposits. The country 
between the Upper and Lower lakes is low and swampy in most 
places, but deposits of coarse fragmental material are found; 
the outlet of the Lower Lake flows through a flat valley of sand 
1 All elevations given in this paper are based upon aneroid readings checked on 
U.S.G.S. elevation for Priest Lake 2,460 feet. As I was often away from this known 
elevation for several days, there is possibility of considerable error. 
