“Under construction” — should be completed mid December 2025
The hike
This hike is about five miles, but the last two miles are an out-and-back trail along the top of the mountain, so folks who want to do only three miles will have an easy return after about two miles (and most of our geologic explorations). You can see the cutoff at the yellow 1 marker on the map below.
Alltrails map
Geology
Ring Mountain is Trip 4 in the Geologic Trips: San Francisco and the Bay Area book (plenty of used copies here or look for it in your local libraries here). The trip is subtitled “Exotic Blocks — Thermometers in the Subduction Zone.”
Things we’ll see/look for
Near Taylor Road, we’ll look at boulders that contain grooves that formed as these boulders moved through the subduction zone. We’ll also find tiny garnets in eclogite rocks.
Transportation, getting there
- Parking is readily available along the road. Watch for traffic when you park.
- From the Larkspur Ferry/SMART train station, it’s about a fifteen minute bike ride.
- Golden Gate Transit doesn’t really get close, but if you can get to the Paradise Drive bus pad, and prearrange it, another hiker can probably pick you up (ask on the Meetup events page if there is anyone who can pick you up). You could also take a Lyft/Uber for the ‘last mile.’
Other web resources
- General info about the park from Marin County Parks: https://www.parks.marincounty.org/parkspreserves/preserves/ring-mountain (includes downloadable map)
- Bay Nature article on Ring Mountain Geology. http://baynature.org/articles/apr-jun-2007/ring-mountain-rocks (June 2007)
- KQED Quest: Geological Outings Around the Bay: Ring Mountain. https://www.kqed.org/quest/14623/geological-outings-around-the-bay-ring-mountain (May 2011)
- Rock carvings on Ring Mountain. http://www.megalithic.co.uk/article.php?sid=19244
- Northern Cal Geologic Society page on Ring Mountain. https://ncgeolsoc.org/field-trip-report-tiburon-peninsula/ (great photos) (Sept 2004)
- Great photomicrographs of thin sections http://mathsci.solano.edu/users/mfeighne/vol1.page2.htm taken by Howard Day and Warren Gray. This page has been deleted, but it can be found here (without the photos): https://web.archive.org/web/20170515195419/http://mathsci.solano.edu/users/mfeighne/vol1.page2.htm
- KMZ map showing geologic map http://getwx.com/Ring_Mountain_Geo_Map.kmz (thanks, Brenor). You can read this using Google Earth or other KMZ capable programs; your web browser may warn you about downloading this file, but it’s safe to download.
Past Meetup hikes
Our past trips to Ring Mountain (with photos and reviews)