Don Edwards National Wildlife Refuge – Fremont

Last exit before the Dumbarton Bridge.

Park in the last parking lot and head south on the Tidelands Trail for a quarter mile.

4 unique bedrock mortars on this metamorphic chert. The only ones we’ve ever seen.

Great tideland walking trails. A different world.

On the trail below we found this displaced 7 cupule rock.Later on we found another possible 3 cupule rock.

Understand that there were thousands of Native Americans living here for ten thousand years before there was a San Francisco Bay.

That slice you see in the Continental Shelf outside the Golden Gate is the remnant of the great river that cut through our Bay Area before sea level rise led to the creation of San Francisco Bay 5 or 6 thousand years ago.

The three little dots on the Shelf are the Farallon Islands which were just nice hills back in the day.