Typical coarse grained Pikes Peak granite on the summit of Bison Peak [Bison Mountain]. Park County, Colorado. Pre-1950.

Typical coarse grained Pikes Peak granite on the summit of Bison Peak [Bison Mountain]. The rapid weathering of the granite along joints is shown in this view. This weathering gives rise to residual and balanced boulders characteristic of the areas where the Pikes Peak granite has been long exposed to mechanical and chemical weathering. Mans figure near base of upper cliff at right gives the scale. Park County, Colorado. Pre- 1950. Figure 9-D in U.S.Geological Survey Professional paper 223. 1950