18 
MUSEUM BULLETIN NO. 11. 
2, profile 1). Corresponding to this there is a steepening of 
stream grade upon going from upland to canyon bottom. 
The West Fork valley floor is made up of a series of terraces 
which occur in irregular patches upon its bottom, or as frag- 
ments often far up the valley sides; similar terraces occur in the 
side stream valleys. The terraces are sometimes complicated 
or obscured by alluvial fans, where side streams enter the valley, 
by rock outcrops, by morainal deposits, and kettle holes. Un- 
modified glacial deposits are rarely met with. A number of 
lakes occur upon the upland and in the valley bottoms. They 
are small and generally quite shallow. Some of them occupy 
rock basins, but in many cases their lower ends appear to be held 
up merely by local deposits of loose glacial detritus or by beaver 
dams. 
Detailed Description. 
The walls of the larger valleys within the quadrangle have 
in general much steeper slopes than the uplands lying between 
them, and this contrast in slope varies as the size and depth of 
the valley. The larger valleys also differ in the shape of their 
cross sections from the shallow troughs upon the uplands. These 
facts have furnished a basis for the division of the topography 
into an upland and valley type. The topography is described 
under the headings of uplands, valleys, lakes and swamps, and 
glacial forms. 
THE UPLANDS. 
The deeper valleys in this quadrangle divide the upland 
surface into a number of blocks. These blocks have the form 
of broad flat topped ridges trending parallel to their bounding 
valleys, and whose surfaces as a whole slope down toward the 
valleys. Since valley trenches grow shallower toward their 
sources, the upland areas tend to merge into each other at such 
places, and again at other places an area between two large 
valleys will be incised by smaller canyons.^; We may divide the 
quadrangle into six principle interfluves, naming them after 
