2021 Map of Shell Reef

About this map

Shell Reef stands as a prominent geological landmark within this arid section of the Colorado Desert, straddling the boundary between San Diego Co and Imperial Co. This modern topographic survey reveals a landscape dominated by complex drainage systems and subtle elevation changes, transitioning from the Lower Borrego Valley toward the western edge of the Imperial Valley. Water sources, while scarce, are critical historical and topographical markers here, evidenced by the presence of Five Palms Spring and Barrel Spring. The terrain is defined by numerous seasonal waterways such as Tule Wash, Arroyo Salada, and San Felipe Cr, which have sculpted the land over millennia. To the west, the rise toward Squaw Peak provides a stark contrast to the sprawling lowlands and washes that characterize the central and eastern portions of the quadrangle.