 Rivers and canyons border east and west; the south of the range is located in Maricopa County, the location of much of the Phoenix metropolitan area.The New River Mountains are part of a region extending southwards from the southeast of the Black Hills of central Arizona.The region contains mesas, hills, and mountain peaks; the region is bordered on the west by the Black Canyon, where the Agua Fria River flows south towards Phoenix, and on the east, canyons where the Verde River also flows south to enter the Phoenix valley.