Saturday, April 8, 8–10 a.m. Join professional geologist and meteor expert Bob Verish and naturalist Les Braund, an expert on lichens and mushrooms, on a geology walk to the waterfall. Learn about the volcanic processes that created the waterfall rocks. See a fossil trapped in the volcanic rock. Meet at the far west end of Park Village Rd in Rancho Peñasquitos 92129. Sponsored by the Friends of los Peñasquitos Canyon Preserve.