LARAMIE REGION, WYOMING 435. 
viewpoint is 8,000 feet above sea-level, or as high as the summits of 
many of the rugged mountain ranges of the Northwest. When a 
closer examination is made, it is obvious to the geologist that the 
gently arched surface just described is in reality a plain of denudation, 
now more or less dissected. This surface passes with very little 
change across the outcrops of many different kinds of rocks. Schists, 
gneisses, porphyries, and gabbros are alike worn to a common level; 
and so slightly do they affect the details of the topography that surface 
forms are of doubtful value in mapping the outcrops of the different 
rock-formations. ‘That the surface is a cut plain rather than a built 
plain is at once obvious, for outcrops of bed rock appear abundantly 
in it, although the majority of them are subdued and rounded, or 
even reduced to the level of the plain itself. In railroad cuts and 
in the open pits at Buford one may see that the granite and other 
rocks constitute all of the foundation, with scarcely any covering of 
soil or transported materials. The rocks are, however, deeply decayed, 
the granite being so soft that it is excavated with steam shovels to a 
depth sometimes exceeding 50 feet. In many exposures only the 
loose granitic gravel is to be seen, and by this alone the hasty observer 
might be misled. In these very exposures, however, one may often 
see quartz veins and small dikes, traversing the loose rubble right up 
to the grass-grown surface of the plateau. This shows that the material 
has not been disturbed. It is simply a thoroughly decayed mass of 
granite and other rocks. 
It is, of course, not to be expected that this nearly level surface 
is a perfect plain. Here and there irregular knobs and piles of ex- 
foliated bowlders rise above it, and a few hills or mountains of con- 
siderable size are scattered here and there over its surface. The 
highest of these are grouped in the Sherman Mountains, which have 
a maximum relief of nearly one thousand feet above the plain. These 
isolated elevations are doubtless monadnocks. Farther east, mark- 
ing the outcrops of the hard Pennsylvanian limestone, there is a series 
of sharp hills or hog-backs which stand higher than the general sur- 
face of the Sherman peneplain. The coarse granite on the west and 
the soft sediments on the east are more easily eroded than the massive 
limestones. 
The identification of the peneplain upon the Sherman uplift is a 
