GEOGRAPHY: W. M. DAVIS 
697 
of the valleys that they followed, and locally overdeepened the valley 
floors into lake basins, at the farther end of which large terminal moraines 
were deposited. One of the Canadian glaciers moved southward along 
the large longitudinal valley known as the Rocky Mountain trough and, 
after reenforcement from Glacier National park, spread out in the broad 
Flathead basin; a brief account of its erosional work, as well as of the 
FIG. 1. OUTLINE MAP OF CANADIAN GLACIERS FORMERLY INVADING NORTHWESTERN 
MONTANA AND NORTHERN IDAHO. 
work of local glaciers in the adjoining Mission range, was given in these 
Proceedings two years ago,^ and a somewhat fuller statement has been 
pubHshed in the Geographical Review} The other Canadian glacier 
moved southward along the Purcell trough farther west and invaded 
the valley of Clark fork of the Columbia river; its work is here summar- 
ized. A full report of the Shaler Memorial investigation on which these 
special studies are based will probably appear in the Annals of the 
Association of American Geographers. 
