Otay Formation

The Otay Formation is a geologic formation in San Diego County, California (United States) and northern Baja California state (Mexico). It is within the Peninsular Ranges province.
Fossils.
It preserves fossils of the Oligocene to Miocene periods of the Cenozoic Era. Fossils in the Sweetwater Formation that underlies the Otay Formation are of the Late Eocene period.