Western Message Petroglyphs indicate historic beaver presence in a San Francisco Bay Area watershed

Recent museum, archaeological, and observer record evidence suggests that North American beaver (Castor canadensis) were historically native to the watersheds of California’s coast, including San Francisco Bay. A wide variety of animals are abundantly represented in Native American petroglyphs and pictographs with their representations fulfilling intentions ranging from the mundane to ceremonial and mythological purposes. However, beaver symbols are poorly represented in California rock art and absent from the San Francisco Bay Area. A novel record, in the form of Western Message Petroglyphs, suggests that a beaver lodge was present in the late nineteenth century in the Alameda Creek watershed, potentially the last evidence of beaver prior to their extirpation in the region by the fur trade.