Triangle Marsh, Archaeological site in Marin County, California, United States

Triangle Marsh is a 31-acre wetland site at the base of Ring Mountain on the Tiburon Peninsula in Marin County. The area includes both marshland and upland habitats that support the broader San Francisco Bay ecosystem.

Pecked curvilinear nucleated petroglyphs on Ring Mountain, along with archaeological recovery there, provide evidence of Native American habitation and suggest that early Miwok peoples exploited marine resources from Triangle Marsh.

The rock carvings on Ring Mountain show that indigenous people used the area for artistic and spiritual purposes. These petroglyphs tell us about the sacred connection between the Miwok and this land.

The site is managed by the Audubon Society with ongoing habitat restoration work happening throughout the year. Visitors should wear sturdy footwear and be prepared for wet and sometimes muddy ground conditions.

The 31-acre marsh is owned by the Marin branch of the National Audubon Society, which restored its upland and wetland habitats with funding from a variety of sources. Pecked curvilinear nucleated petroglyphs on nearby Ring Mountain suggest early Miwok peoples exploited marine resources from the marsh.