Canyon Trail Park Petroglyph Boulder20+ bedrock mortars and 175+ cupules on one chlorite blueschist boulder.Elevation 141 ft.CA-CCO-152This rock is in Canyon Trail Park on a branch of Baxter Creek. Baxter Creek flows into the Bay near Stege, a long-vanished neighborhood on the old shoreline of San Francisco Bay, northwest of Albany hill. Some of the […]
Lake Del Valle, Campsite 7414 cupule rock and 1 small bedrock mortar on rock in the nearby creekElevation 714 ft.Thanks to Joel and Alex for discovering these rocks.The cupule rock was likely moved here. The patterns of cupules appear non-random, which suggests they may have had representational functions.This shallow mortar is difficult to make out […]
Whittell Marsh ShellmoundNear the tip of Point Pinole.Elevation 7 ft.N. C. Nelson counted 425 shellmounds in his seminal article “Shellmounds of the San Francisco Bay Region,” University of California Publications in American Archaeology and Ethnology, Vol. 7, No. 4, Putnam and Kroeber editors, The University Press, 1909. Very few can be seen today. This is […]
Winter Solstice alignmentElevation 734 feetThe rocks in this alignment are the only ones in the immediate vicinity.Dave hit the jackpot when he discovered this rock alignment, which lines up nicely with the gap between Mt. Diablo and North Peak.There is a 360 degree view from this hilltop.Awaiting the sunrise.Winter solstice December 21, 2010. Experts assure […]
Sunol Ridge Prayer CircleStacked-rock prayer circle.Elevation 1664 ft.Our jaws dropped when we saw this near the bottom of a little hollow just below the top of Sunol Ridge.A closer look at the geoglyph.Photograph by Bob BardellPart of the “spine” of this stone circle is a natural rock outcrop.This site is on private property. One should […]
Below McClure Springs75 yard long rock alignment overlooking the South Bay.Elevation 1908 ft.Some of the rock alignments in the Mission Peak area are probably natural formations. Others are clearly man-made. We believe this alignment is a member of the latter class.A close look at the stacked rocks.