Archeological findings verify the occupation of San Diego County by Native Americans going back over 10,000 years, though little is recorded of their history before 1542, when Juan Rodriguez Cabrillo sailed into San Diego Bay and claimed the local territory for Spain. The native population at that time is estimated to have been 20,000, just as it is today. There are 18 reservations in the San Diego County area (17 of which are currently functioning), more than in any other county in the United States. The four primary tribal groups making up the Native Americans of the San Diego County area are the Kumeyaay (also known as Diegueño), Luiseño, Cupeño, and Cahuilla. Each of these groups has faced many hardships and setbacks while attempting to rebuild their nations to the proud peoples they once were, still are, and always shall be.