Temescal Valley in California is a graben rift valley in western Riverside County, California, a part of the Elsinore Trough. The Elsinore Trough is a graben between the Santa Ana Mountain Block to the southwest and the Perris Block on the northeast. It is a complex graben, divided lengthwise into several smaller sections by transverse faults. The Temescal Valley is one of these graben, at the northern end of the trough.