Rock  |  Water  |  Wood  
Granite defines Yosemites landscape.  Shaped by glaciers long ago, the rock continues to be worn by the elements; temperature changes and rain, snow and ice cause and expand cracks.  Additionally lichens, moss, ferns and other plants gain hold and cause further wear.  Rockfalls happen every year in the Park; the National Park Service reported 43 documented rockfalls in 2012, with an approximate cumulative volume of about 700 cubic meters (about 2,100 tons).
The view from Olmstead Point shows vast expanses of granite.

Iconic faces of granite--El Capitan and Half Dome.

Lembert Dome, Tuolumne Meadows.

Pothole Dome, Tuolumne Meadows.

A rock face across the road from Tenaya Lake.  In the vignette above, rock climbers make their way along an edge where a piece of granite has sheared off.

Erratics, boulders that have been carried along and deposited by glaciers, add a whimsical touch to the landscape.  (Top, Pothole Dome; bottom: Lembert Dome).

Small bits of glacier polish on Pothole Dome reflect the sun.  In some areas, near Tenaya Lake for example, there are fairly large stretches where in the early morning/late evening the reflection off the glacier polished rock can be quite blinding.

Inclusions on Pothole Dome.

Moss on Pothole Dome.

A vein near Olmstead Point includes a worn area with a small pine tree.

A vein (l) and a crack (r) on Pothole Dome.

A fallen tree contrasts with the rock on Lembert Dome.

Water meets rock at Saddlebag Lake in the Inyo National Forest near the border to Yosemite.

Link: Geology - Yosemite National Park