on the island are the remains of several shellmounds left from prolonged occupation by native americans, most likely people from the ohlone tribe, sustained by the abundant sea life in the surrounding bay. the park district's 1976 resource analysis identified the tribes as "huchium [huchiun] or perhaps chochenyo", and speculated that as many as 15,000 people might have lived on the land over the course of 2,000 to 3,000 years.