Parker Valley is a stretch of the Lower Colorado River Valley along the Colorado River in southwestern Arizona and southeastern California, where the Sonoran and Colorado deserts meet. Shaped by the river and surrounding landforms, it includes riparian habitat such as mesquite bosques as well as irrigated agricultural land supported by the river. The region is fed by the Bill Williams River, Bouse Wash, and Tyson Wash, all draining lands east of the Colorado. It also forms part of the Colorado River Indian Reservation and the northern edge of the La Posa Plain, linking desert habitats, river vegetation, settlements, reservation lands, and farmland along a major Southwestern waterway.