The upper crust of the central Mojave Desert was extended and thinned during early Miocene time by three processes (1) low-angle normal faulting; (2) high-angle normal faulting in several episodes; and (3) extension fracturing. The first two processes appear to have affected the entire breadth of the extended area, but the third process was restricted to narrow zones. Processes 1 and 2 developed in at least two half-grabens that were kinematically linked by a transform fault. Each half-graben contains a family of similarly oriented high-angle normal faults that facilitated the extension of the upper crust. Evidence from one of the half-grabens suggests that the high-angle faults originally dipped at higher angles and were mechanically linked with a gently northeast-dipping normal fault (detachment).