Mission Santa Catalina was founded on the margins of the Spanish colonial frontier in northern Baja California, but over time it became an important place in the indigenous landscape of the region. Dominican friars established the mission at a crossroads of native interaction, and recent archaeological, archival, and ethnographic research suggests that indigenous mission neophytes continued to engage in dynamic social and economic relationships with other native groupsthroughoutthecolonialperiod.Atthesametime,however,thediversenativepeopleswholivedatSantaCatalina formed new bonds to each other and to the lands around the mission itself. Together, these two processes suggest that the mission’s neophyte population was not isolated from the broader indigenous landscape, and that although it was marginal from the point of view of the Spanish, Santa Catalina was—and continues to be—an important place in native Baja California.

The X-ray fluorescence analysis of obsidian artifacts from four study areas in Baja California, Mexico, suggests regional and local patterning in the geological sources used by indigenous hunter-gatherers during the late prehistoric and colonial periods. Obsidian artifacts were typically made from materials from the closest geological source, creating a distinct north-south pattern of obsidian distribution. In the northern region of Baja California, this pattern appears to correspond to ethnographically-documented language boundaries. However, within each study area, particular sites exhibit higher degrees of obsidian source diversity than others—a pattern that may suggest chronological or social variation in access to particular obsidian sources. Unexpectedly, projectile points do not exhibit noticeably higher levels of source diversity when compared to an aggregate of all other obsidian artifacts. Together, these patterns offer a baseline of knowledge about regional obsidian distributions and point toward potential avenues for future research on obsidian availability and conveyance in Baja California.

The enamel proteome includes a range of proteins that are well-preserved in archaeological settings but have so far received less study than those associated with sex-estimation of enamel. We look beyond sex-specific sequencing of amelogenin to investigate the potential of several serum proteins, including immunoglobulin gamma (IgG), the major immunoglobulin found in blood serum, and C-reactive protein (CRP), which is associated with inflammatory response, to provide insight into the health and stresses experienced by individuals in the past. We apply this approach to enamel samples from Mission-Period ancestral Ohlone interred at Asistencia San Pedro y San Pablo (CA-SMA-71/H; n = 11). For comparison, we also examine enamel from historic-period European-Americans interred in the City Cemetery in San Francisco (n = 12), and extracted third molars from present-day military cadets (n = 8). Results indicate that IgG is elevated among individuals at the asistencia relative to samples from present-day military cadets, and historic City Cemetery individuals (ANOVA with post-hoc Tukey Kramer tests, p < .02). Further, the inflammatory protein CRP, normally expressed at much lower levels than IgG, was present in 55% (6 of 11) of the asistencia samples, and in 17% (2 of 12) of the historic City Cemetery samples, but was not detected in enamel samples from present-day military cadets. While more studies are needed, we argue that the difference in IgG could reflect higher levels of chronic diseases such as tuberculosis among Ohlone living within the Mission system, and the presence of measurable amounts of CRP could relate to higher degrees of physical, social, and emotional stresses. To our knowledge, this is the first paleoproteomic study of immune proteins in tooth enamel. The ability to track immune responses during tooth formation could provide valuable and high-resolution information on ancient health and disease at the level of the individual over archaeological time-scales.