A Little Known Region in Northwestern Montana. 205 
proper, and the Cascade range is very mountainous. The ranges are 
broken and irregular. Short spurs and ridges trending in various direc¬ 
tions give rise to a net-work of valleys. Through this labyrinth the 
ice-streams made their way. Some of them found more or less direct 
passage into the great Flathead valley and there died a natural death. 
Others were caught by the transverse spurs and carried up over the main 
range from whence they descended to the plains on the east. 
The tendency toward a southerly movement may indicate a northern 
origin for the ice. It is evident, however, that local supply would be 
abundant, if, indeed, it might not be sufficient to account for all the 
glaciation observed. 
Madison, Wisconsin, December 29,1891. 
