The Big Bear block with its low-relief plateau surface. Note the flatness of the top in comparison to the steep northern margin and the steep canyons that incise into the plateau. The North Frontal thrust systems bounds this block along the escarpment shown. The entire block has been uplifted along the northern thrust shown here and the smaller Santa Ana thrust on the south.
 
 

The high country of the San Bernardino Mountains, here showing San Gorgonio Peak. This peak reaches 11,502 feet (3506 m) and is the highest point in southern California.
 
 

Another view of the San Gorgonio block. Note its flattish, east-west shape that is similar to a whale-back, in comparison to its steep northern and southern margins. This block has been warped into a plunging antiform due to convergence in the stepover in the San Andreas fault at San Gorgonio Pass.
 
 

The Yucaipa Ridge block. This block is incredibly steep, consisting of a knife-edge ridge and flanks that are steeper than repose. This block has been pushed up within the strands of the San Andreas fault over the last few million years.
 
 

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