Alvarado Park
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Alvarado Park


Alvarado Park
2 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 study some of the cupules on this outcrop. An archetypal cupule cavity is the size of a golf ball cut in half. Many of the cupules here are larger than that.


Cupules are densely packed on the rocks here.

Photograph by Bob Bardell

For more information on cupule petroglyphs see Cupule Petroglyphs in the Diablo Range by E. Breck Parkman in the Journal of California and Great Basin Anthropology Vol. 8, No. 2, pp. 254-55 (1986).

For an in-depth study of PCNs see Donna Gillette’s 2011 dissertation Cultural Markers on the Landscape: the PCN Pecked Curvilinear Nucleated Tradition in the Northern Coastal Ranges of California.

Heather points to a PCN. Note the circular groove and the raised “nucleated” center.


We believe the trinomial for this site is CA-CCO-125.