Contra Costa Cactus Posted July 12, 2011 8:56 am & filed under . In the heart of Contra Costa County, between the Carquinez Straight and the John Muir National Historic Site, we find a stand of spineless Opuntia. Delicious! Photo sent from Briones by Donna, who wants it removed. Cactus and Succulents Bamboo Perennials Carnivorous Plants Airplants Search for: June 2026 M T W T F S S 1234567 891011121314 15161718192021 22232425262728 2930 « Mar