The dam is constructed on the sediments of the Turlock Lake and Mehrten formations, and a number of interesting fossils have been found in the area: mastodons, camels, horses, huge tortoises, and gigantic 9-foot-long tusked (really!) salmon.
caltopo.com and found that we were looking at the heart of the Yosemite high country. Here are the caltopo.com images for the last two views above. The first shows from left to right Mt. Simmons, MaClure, Lyell, and Clark.