Excellent tide pooling can be had along mile-long Duxbury Reef, the largest shale intertidal reef in North America. Look for sea stars, barnacles, sea anemones, purple urchins, limpets, sea mussels, and the occasional abalone. But check a tide table (www.wrh.noaa.gov/mtr/marine.php) or the local papers if you plan to explore the reef—it's accessible only at low tide. The reef is a 30-minute drive from the Bear Valley Visitor Center. Take Highway 1 south from the
center, turn right at Olema-Bolinas Road (keep an eye peeled; the road is easy to miss), left on Horsehoe Hill Road, right on Mesa Road, left on Overlook Drive, and then right on Elm Road, which dead-ends at the Agate Beach County Park parking lot.