This thesis conducts historical research into Swanton Pacific Ranch in the County of Santa Cruz, an interdisciplinary facility for education and research managed by Cal Poly’s College of Agriculture, Food and Environmental Sciences. The study seeks to determine whether there have been discernable changes in vegetation alliances (communities), spatially or in type, within a 110-acre Study Area from the early twentieth century to the present day and how the changes compare with other similar historical analyses in California. Historical farming and ranching uses of the area are researched, and two family case studies are presented as paradigms of potential changes to vegetation as well as the connectivity with the larger socioeconomic context of Italian immigration into California. Examination of the vegetation alliances over the course of the historical study period utilizes several types of historical imagery, including twentieth-century aerial photography, ground level photography and nineteenth-century maps. This thesis diverges from scholarship that posits substantial alteration of ecological systems by anthropogenic activities by arguing that the primary alliances and geospatial borders of the vegetation in the Study area have remained essentially stable, i.e., unchanged at a macro level, since at least the early twentieth century, and that this stability has persisted despite long-term agricultural activities. This thesis contributes to the historiography of Swanton Pacific Ranch by providing a preliminary exploration of the botanic resources and the attendant anthropogenic agricultural activities on the land that may have affected those resources. It provides a framework for further study of Ranch resources as well as the cultural context of the agricultural history of the North Coast-Santa Cruz region.