The Algodones Dunes, which border old Cahuilla shorelines, were formed by sand blown from Lake Cahuilla. This theory was first formulated in 1923. The process occurred either immediately after the lake reached modern highstands, or during earlier higher stands. Most likely, sand was transported to the dune field during times where the lake receded and its bed was exposed to wind. Various stages of Lake Cahuilla may correspond to waves of migrating dunes.