For decades the San Francisco Estuary, which includes San Francisco Bay and the Sacramento-San Joaquin Delta, has been routinely described as “the largest estuary on the west coast of North America.” This appeared in publications of all types, presumably to emphasize the importance and unique nature of the estuary. But this claim is wrong. While the San Francisco Estuary is quite large, with many unique features, the Salish Sea Estuary is the largest by far.