The San Francisco garter snake, a subspecies of the common garter snake, is found in scattered wetland areas on the San Francisco Peninsula from approximately the northern boundary of San Mateo County south along the eastern and western bases of the Santa Cruz Mountains, at least to the Upper Crystal Springs Reservoir, and along the Pacific coast south to Año Nuevo Point, and thence to Waddell Creek in Santa Cruz County.
The San Francisco garter snake, a subspecies of the common garter snake, is found in isolated wetland regions on the San Francisco Peninsula from roughly the northern edge of San Mateo County south along the eastern and western slopes of the Santa Cruz Mountains to at least Upper Crystal Springs Reservoir, and along the Pacific coast south to Año Nuevo Point, and then to Waddell Creek in Santa Cruz County.