Geophysical Investigation of Mission San Francisco Solano, Sonoma, California

Recent advances in mission archaeology advocate for studies beyond the mission church and quadrangle in order to better understand their spatial organizations and how they were embedded within the landscapes of indigenous populations. This raises the question of how to implement such studies in areas impacted for years by urban development, which has made it difficult to detect archaeological remains using standard pedestrian-survey methods. This article advocates for the use of geophysical survey as part of the mix of field strategies. Archaeologists undertook fieldwork at Mission San Francisco Solano in Sonoma, California, to assess the potential of employing geophysical-survey methods in contexts characterized by extensive post-mission reuse. The results indicate that ground-penetrating radar and resistivity surveys are capable of detecting earlier mission architectural remains that can be differentiated from the remains of post-mission urban development from the late 19th and early 20th centuries.