Ring Mountain on the Tiburon Peninsula in Marin County is one of the northern Bay Area’s most culturally and scientifically significant landscapes. The ancestral home of the Coast Miwok, it preserves Coast Miwok petroglyphs and deep cultural ties. Later associated with the Reed family and named for George E. Ring, it is especially important for serpentinite geology, rare metamorphic rocks, and unusual soils that support unique plants, including the world’s only Tiburon mariposa lily population. After limited military use and a threatened development in the mid-1960s, preservation efforts gradually protected much of the mountain, which today remains a habitat-rich open space for recreation, research, and education.