Coal Mine Ridge in Portola Valley

Today I led my College of San Mateo class on a nearly six mile loop through Coal Mine Ridge on the Portola Valley Trails and through part of Windy Hill Open Space Preserve. Our route took us along the San Andreas Fault and revealed an extraordinary diversity of trees, bushes, and flowering plants.

We met near the intersection of Alpine Road and Willowbrook Drive in the town of Portola Valley. The small parking lot on Alpine Road was full, but there was plenty of parking on Willowbrook. From there we crossed Alpine and headed uphill to the Old Spanish Trail. We followed that trail all the way to two sag ponds formed where a curve in the San Andreas Fault caused the land to drop and fill with water. We ate lunch at the pond on Lake Road. While lunching, we saw a pond turtle, a grebe, and a blue heron.

After lunch we headed south on the Lake Trail to Alpine Road. We then walked downhill on Alpine Road to the Eagle Trail in Windy Hill Open Space Preserve. We crossed Corte Madera Creek on an old stone bridge and continued on back to our starting point.

We saw blue oaks, white oaks, black oaks, live oaks, madrone,  and bay trees. We enjoyed many flowering plants, which were abundant despite the drought. Here is a partial list of flowering plants:
slim solomon's seal, hairy honeysuckle, globe lilly (fairy lantern), soap lilly, flax, Ithu

rial's spear, Douglas Iris, hedge nettle, blow wives, several species of Clarkia, ookow, larkspur, mariposa lilly, pitcher sage, chamise, Chinese houses, crimson columbine, golden poppies, vetch, and cow parsnip.

TO GET THERE... from Highway 280 take Alpine Road south to the intersection with Willowbrook Drive.