Los Osos Oaks State Natural Reserve is an 85-acre California state park in Los Osos Valley on the Central Coast that preserves a rare landscape of centuries-old coast live oaks growing on relict sand dunes. Established in 1972, it protects a distinctive oak woodland and important habitat, including the only known location of the critically endangered lichen Sulcaria isidiifera. The surrounding area also preserves a deeper human past, with nearby archaeological sites linked to the Chumash and dating to at least 1200 CE. Although threatened with closure during California’s budget crisis in 2008 and again after the 2009 special elections, the reserve remained open through systemwide cuts.