Accelerator mass spectrometry (AMS) dates for nine shell beads and two shell ornaments are used to test the application to Orange County of a temporal sequence developed for the Santa Barbara Channel region. Olivella cupped, Olivella oblique spire-removed, Olivella end-removed, Mytilus disc, and Megathura small square ring and Megathura oval ring beads/ornaments fell within time ranges predicted by the bead/ornament chronology developed by Chester King (1981, 1990) for the Chumash area. Olivella biplicata barrels and caps seem not to have been occurrences of King's Late Middle or Late periods in Orange County, but rather there appears to have been a switch to Gulf of California Olivella dama shells for local barrel and cap manufacture.

AMS radiocarbon assays confirm that shell fishhook and line fishing was a feature of early Late Holocene and Intermediate Cultures period subsistence technology in coastal Orange County. Other data support a similar development of coastal line fishing in southern and central California beginning no earlier than the third millenium B.P. However, limited data from San Clemente Island suggest shell fishhooks were employed prior to that time. We suggest that AMS dating be applied to San Clemente Island fishhooks to help clarify the relationship of the island data with established fishhook sequences for Orange County and other parts of California.