ALA-481
Mortar Count: 2
Open
Alvarado Park
Mortar Count: 2
Open
Black Hills Trail
Mortar Count: 3
Open
Camp Confluence
Mortar Count: 1
Open
Canyon Trail Park Petroglyph Boulder CA-CCO-152
Mortar Count: 20
Open
Chitactac
Mortar Count: 75
Open
First Terrace
Mortar Count: 31
Open
Lower Volvon Village
Mortar Count: 200
Open
Lynch Canyon Rancher Petroglyph Rock
Mortar Count: 13
Open
Mira Vista Park
Mortar Count: 10
Open
Monte Bello Open Space–headwaters of Stevens Creek
Mortar Count: 12
Open
Ring Mountain #2
San Marin
Stromer Spring
Mortar Count: 25
Open
Sulphur Spring
Mortar Count: 5
Open
Upper Crow Creek
Mortar Count: 3
Open

Feature: Petroglyphs

RingM1

Ring Mountain #2

Ring Mountain #2Multiple PCNs and fantastic viewsElevation 488 ft.Thanks to Danielle for getting us back out to Ring Mountain.A PCN is created by pecking a circular or oval groove in a rock (typically schist in the Bay Area) leaving a raised “nucleated” center that may itself be subject to further manipulation.For an in-depth study of […]

AlvaradoPark2

Alvarado Park

Alvarado Park2 bedrock mortars, 275+ cupules, 2 PCNs, and midden behind gazebo.This chlorite blueschist outcropping on Wildcat Creek has more cupules on it than any other we know of in the Bay Area. Was it just the blueschist found here and on Baxter Creek that attracted cuple-makers, or was something else at work?Jim and Heather […]

SanMartinPCNs1

San Marin

San MarinMultiple PCNsElevation 174 ft.A form of rock art known as the pecked curvilinear mucleated (PCN) petroglyph survives in a number of North Bay locations and can be found throughout the Coast Range mountains from the Oregon border to Santa Barbara.For an in-depth study of PCNs see Donna Gillette’s 2011 dissertation Cultural Markers on the […]

Black-Hills-Trail-Possible-PCN

Black Hills Trail

Black Hills Trail.Three bedrock mortars, a possible PCN, and a slick.Elevation 1520 ft.Pecked curvilinear nucleated petroglyphs are not supposed to occur in Contra Costa County.We’re not so sure.

StromerSpring

Stromer Spring

Stromer Spring25 bedrock mortars, cupules, and PCN-style petroglyphsElevation 2023 ft.We used to drink from Stromer Spring in the not-so-distant past. The Park District warns against doing it now.A nice, single-track trail passes near here. We followed it many times without ever stopping to examine these rocks. If we considered them at all, we dismissed them […]

CampConfluence

Camp Confluence

Camp Confluence1 bedrock mortar on the north fork of Kaiser Creek.There’s supposed to be a petroglyph boulder on the upper reaches of Kaiser Creek, but we’ve never been able to find it. We did find this single mortar and little camp though.