Together they produce a down-dropped block which forms the Owens Valley. This type of fault-bounded valley is called a graben. A fault-bounded ridge is called a horst. Where the dip of a normal fault's surface is very gentle or almost flat, it is referred to as a detachment fault or low-angle normal fault. Detachment faults are common in the desert areas of California.
Reverse faults are dip-slip faults in which the hanging wall moves up relative to the footwall.
The Sierra Madre fault zone of southern California is an example of reverse-fault movement. There the rocks of the San Gabriel Mountains are being pushed up and over the rocks of the San Fernando and San Gabriel valleys. Movement on the Sierra Madre fault zone is part of the process that created the San Gabriel Mountains. A thrust fault is a reverse fault with a gently-dipping fault surface. Thrust faults are very common in the Klamath Mountains of northern California.