The Front Range of Colorado represents the easternmost range of the Southern Rocky Mountains, and extends from the valley of the Arkansas River near Canon City, Colorado, northward to the Wyoming line. In northern Colorado it branches into the Medicine Bow Mountains on the west and the Laramie Range on the east (Fig. 1). Details of the topography of the region can be found on the United States Geological Survey topographic maps for the quadrangles outlined in Figure 1. A study of these maps conjointly with the text is recommended.
The Front Range represents a great anticlinal uplift, locally broken by both normal and reverse faults, now thoroughly truncated and highly dissected by streams and glaciers.
Except for a few relatively small inliers of sedimentary rocks, which were either faulted or folded down into the crystallines and thus preserved from erosion, the Front Range consists of pre-Cambrian and Tertiary . . .