Not many oysters from Willapa Bay make it to half-shell service. Few Willapa oysters develop the perfect form that most restaurants seek, which is a shame, because the classic Willapa flavor—lightly salty, sweetly cucumber, and delicate, as pure sea as you get in a Pacific oyster—is quite nice and markedly different from most Washington oysters. The name you are most likely to encounter is that of Willapa Bay itself. It could be from many producers, could be dredged or hand-picked, could be natural-set or hatchery seed. What you can count on is that it will be from the cleanest estuary in the United States. Look for a small, khaki shell with deep ridges and a clean white interior.