today than geoducks, which have gained a marketing cachet. Identification is important. Best recipes vary with species. For resource sustainability, the Washington State Department of Fish and Wildlife sets size and bag limits for these clams. The Department of Health sometimes closes beaches for public health and safety. The Department of Health Marine Biotoxin web site has current information. King County has a well-illustrated clam identification procedure . Some clammers find horse clams are not as tasty as others, so it's not unusual during clamming season to find horse clams left behind on the beach. The shells are more fragile than they might appear, so it is critical that they not be damaged when first digging if they are not kept. The clams will soon die if abandoned. The adults are unable to rebury themselves—they need the pressure of their surroundings to remain intact and maneuver. They can't hold their two big valves together, protecting their soft tissues. Responsible diggers carefully rebury them to about the depth at which the clams were found. Prehistorical exploitation Early exploitation of horse clams is known by Native Americans on the Pacific Ocean coast of California. For example, archaeological recovery from Chumash sites in San Luis Obispo County has revealed use of horse clam shells as a scoop implement. An unusually well decorated specimen was found at the present day town of Morro Bay during archaeological excavation. Notes and references Bibliography C. Michael Hogan (2008) Morro Creek, The Megalithic Portal, ed. A. Burnham, February 28, 2008 Further reading Abbreviated edition of the clam identification key by the Washington State Department of Fish and Wildlife at the King County Department of Natural Resources Science: Geoduck and Horseclam Biology, an overview by Underwater Harvesters Association, British Columbia, developers of underwater farming. Mactridae Marine molluscs of North America Molluscs of the Pacific Ocean Molluscs of the United States Western North American coastal fauna Fauna of California Seafood in Native American cuisine Bivalves described in 1850