2023 Map of Shell Reef

About this map

The arid landscape of the Imperial Valley is defined by a complex network of ephemeral drainage systems and desert springs. Intersected by the boundary of San Diego Co and Imperial Co, this area features prominent geological and hydrologic markers such as Shell Reef and the expansive Lower Borrego Valley. Water sources, though rare, are clearly documented at Five Palms Spring and Barrel Spring, providing vital points of orientation in a region dominated by major dry washes like Tule Wash, Arroyo Salada, and San Felipe Creek. The presence of the indigenous place name Mat Puy Nah Achhuukaayp and the locality of Kunklen indicate a landscape shaped by both natural topography and human habitation. This 2023 survey details the contemporary state of these desert washes, including Surprise Wash and Tarantula Wash, illustrating how the desert floor is carved by seasonal runoff.