Ring Mountain covers 385 acres, preserved in part as public lands thanks to the efforts of Phyllis Ellman, a Tiburon resident known as “Mother Botany,” who fought to save the area from development during the building boom of the 1970s. Ellman, who died in 2009, has a trail named after her, a loop of about 2 miles that is considered an easy route. It’s also a popular one, but just one of many options on this network of trails that criss-cross the reserve.
Before Ellman and her efforts, there was a man named George Ring, a dairy farmer who, despite his New Hampshire ancestry, bought enough land in this part of Marin to put his name on the landscape. And before Ring, there were the indigenous peoples, the Coastal Miwok, who spent enough time around what would be called Ring Mountain that they left petroglyphs that some say are over 2,000 years old.
The engravings seem to have specific contours for this part of the continent, and consist in part of rounded glyphs whose meaning has been lost in layers of settlements and land changing hands. The most famous site of these petroglyphs is Petroglyph Rock, but it is difficult to distinguish the original work of the Miwok people from the destructive handiwork of newcomers.
In addition to this special record of human history on Ring Mountain, the reservation is home to several other unique features that set it apart from the other trail-strewn mountains around Marin that offer awe-inspiring 360-degree views. Yes, you get panoramic views of the Bay Area from the open spaces of Ring Mountain, including San Francisco to Mount Diablo to Mount Tamalpais. But if you take a moment to look down instead of around you, at the right time of year, you might see something that only exists in this place.
The mountain is said to be home to nine plant species that are considered sensitive or protected, and one of them, the Tiburon mariposa lily, is found nowhere else on Earth. This plant, which you can look for in late spring, grows here in the crevices of serpentine outcrops typical of Ring Mountain.

The colors of serpentine, California’s state rock, are reminiscent of the stormy waves of the Pacific Ocean, changing from a deep blackish hue to a pale seafoam green laced with billowing white. There are reportedly three colonies of the Tiburon mariposa lily in this open space, specifically adapted to the potential toxicity of the serpentine and serpentine-soaked soils.
Another rare flower that blooms on the Ringberg in May is the Tiburon jewel flower, or black jewel flower. The domain houses one of only two colonies of the plant not only in Marin but around the world (the other occurs just southeast of Ring Mountain, in Old St. Hilary’s Preserve).
The serpentine rocks are also a special attraction of Ring Mountain, as they provide one of the few places in Marin to climb. There’s Turtle Rock, so named for the somewhat turtle-like appearance of the head and carapace when viewed from certain angles, and a huge and irresistible appeal for those who like a fast scramble. And then there’s Split Rock, with a bit of bouldering and some problems to tackle. The climbing tops out at 50 feet, but it’s a rare opportunity in Marin.
As regards hiking, there’s the Phyllis Ellman Loop, or you can just wander the intersecting network of trails and fire roads, most of which are impassable but with some minor windings in clumps of trees, until you get tired of exploring. While you’re at it, see if you can find remnants of the Army’s anti-aircraft guns that represent yet another chapter in Ring Mountain’s history.
Accessibility: There are a handful of ways to access the trails on Ring Mountain. Most involve taking the winding Paradise Road to the trailhead, where you’ll find limited street parking. There are gates on Taylor Road, on Paradise Drive or on Reed Ranch Road. Dogs are allowed on a leash. There are no facilities at Ring Mountain.
Emily Willingham is a Marin science journalist, book author, and biologist. You can find her on Twitter @ejwillinghamphd or on Mastodon at [email protected].