A deeply buried shell midden (CA-SRI-6) on Santa Rosa Island, California appears to have been a residential campsite occupied about 9300 years ago. Although few artifacts were recovered from this Early Holocene component, faunal remains suggest a heavy reliance on marine resources, probably supplemented by terrestrial plant foods. Dietary reconstructions suggest that shellfish (especially abalone) provided about 85% of the estimated meat yields, fish about 14%, with birds and sea mammals each contributing less than 1%. These data suggest that Early Holocene adaptations on the Channel Islands were distinct from the coastal mainland in many ways and that maritime hunter-gatherers had adapted to a variety of Pacific Coast habitats by this early time.