Ring Mountain is an elevated landform on the Tiburon Peninsula in Marin County, California. This mountain was named for George E. Ring, who served as a Marin County Supervisor from 1895 to 1903. A number of rare and endangered flora inhabit Ring Mountain. The mountain's twin summits consist of serpentinite, a rock which is very high in magnesium, producing soils of unusual chemistry (serpentine soil). The landscape is strewn with many sizable boulders which exhibit a variety of lithologies including high-pressure metamorphic rocks of amphibolite, blueschist, greenschist, and eclogite grade.