Living on the Edge: Environmental History at Mussel Rock, Daly City, California

Abstract

This study examines the environmental and land use history of Mussel Rock from Ohlone settlement to the present. Mussel Rock is home to a notoriously unstable garbage landfill, which sits directly on top of the San Andreas Fault Zone and the second largest active landslide on the California Coast. Some people embrace Mussel Rock for its unique geography, history, and beauty, and choose to live here with little regard for the potential calamity resulting from fault movement, landslides, and other erosion processes. Among the geologic and coastal processes that have shaped the geomorphology and ecology of Mussel Rock, the San Andreas Rift Zone and Mussel Rock Landslide are the most significant entities. Yet, at a local level and on a shorter time scale, human alteration and modification of the landscape made a substantial environmental impact. The alteration of the landscape by human activity, including residential subdivisions and a municipal landfill, have placed its residents directly at risk from seismic and landslide hazards. Poor land-use decisions combined with natural processes threaten to push the Mussel Rock area 'over the edge' of the continent.