First excavated in 1938, the site of Muscupiabit (CA-SBR-425/H) has long been a subject of archaeological research in the San Bernardino Mountains. Previous excavations at the site have either been unpublished or limited in scope. A primary goal was to obtain a radiocarbon date for the site, giving a definitive age to the site. Other goals included determining the population size of Muscupiabit as well as the function of the site and its place in the Serrano settlement system. To obtain dateable material, an excavation was conducted in hopes of locating a thermal feature. An intact thermal feature was found and charcoal was recovered. In order to adequately address the proposed research questions, museum collections were used to gain a larger sample size. A large quantity of artifacts had been excavated in the 1980s but were never analyzed. Between those excavations and the 2017 excavations, 7 units were analyzed. Additionally, population records from the Spanish mission system were analyzed to address research questions about population size. Based on a radiocarbon date, shell bead types, and population records, it appears that Muscupiabit was occupied in the late 17th/early 18th century and was likely abandoned by 1815. Despite its location along a trade route, the site does not appear to have been controlling trade. Muscupiabit was intermarried with other villages but it’s level of political independence cannot be determined at this time.

Damage zones adjacent to or associated with faults are important to the geologic community because of their implications to hazards and their ability to preserve evidence for, and show history of, slip, fluid flow, and deformation associated with large strike-slip faults. We examine two fault zones in southern California where fault zone damage is expressed. We revisit the drilled crystalline core from the Cajon Pass California drill hole, 4 km northeast of the San Andreas fault (SAF), and 1 km north of the Cleghorn fault, to perform a systematic structural analysis of deformation and alteration associated with strike-slip faulting at the site. The core preserved 19 fault zones, 11 of which were not previously identified. The most significant fault is a fully intact steep-dipping fault zone at 3,402 m depth with potassium feldspar and epidote alteration. This fault correlates well with the nearby left-lateral Cleghorn fault. The extent of deformation varies within the core, and is controlled by the size of the fault zones intersected by the core. The extent of deformation varies and is controlled by the size of the faults the core intersected. We also examined the nature of right separation across the Clark fault damage zone along the Santa Rosa segment using a marker assemblage of biotite, hornblende-bearing tonalite - marble - bearing metasedimentary rocks - migmatite located in Coyote Mountain and the southeast Santa Rosa Mountains. Separation measured from this study is 16.8 km + 3.67 km / -6.03 km. Our measurement uses the updated location of the Clark fault in Clark Lake Valley and matches a distinctive lithologic contact across the fault instead of matching the diffuse western boundary of the Eastern Peninsular mylonite zone as previously used. We calculate the errors associated with projecting the contacts across Quaternary cover to the trace of the Clark fault, and consider a range of projections. Additional strain may have been accommodated in folds and small faults within the damage zone of the San Jacinto fault zone. Two large map-scale folds deform the marker assemblage near the San Jacinto fault zone and we tested whether Cretaceous ductile deformation or brittle late Quaternary right slip produced the folds.