Geologic map of the Hidden Hills Ranch Quadrangle, Clark County, Nevada

The prominent structural feature in the Pahrump Valley is the right-lateral Pahrump-Stewart Valley fault system (PSV) (Anderson and others, 1995b), which is the central segment of the State Line fault system as defined by Blakely and others (1998). The main trace of this fault system, as shown in figure 1A, strikes northwest along the California-Nevada state line through Pahrump and Stewart Valleys (Anderson and others, 1995b). Hoffard (1991) describes three separate segments of the PSV within the Pahrump Valley (fig. 1B). The East Nopah fault zone (ENFZ) is a narrow band of right lateral, strike-slip faults along the eastern front of the Nopah Range. The Pahrump Valley fault zone (PVFZ) is a wider band of right-oblique-slip faults through the center of the Pahrump Valley and extending northwest into the Stewart Valley fault zone (SVFZ). The West Spring Mountains fault zone (WSMFZ) is a band of high-angle normal faults that strike north along the western front of the Spring Mountains and may represent a splay of the PVFZ.