A fauna of 42 larger invertebrates, chiefly mollusks, occurs in late Pleistocene marine terrace deposits near Cape Blanco, Oreg. Marine invertebrate fossils are rare in the northern Pacific coast region. Composition of the fauna, and its relationship to the shoreline of maximum marine inundation, suggest that the assemblage inhabited a sandy substratum in shallow offshore waters. Many paired valves of Schizothaerus, Saxidomus, and Macoma, preserved in place, indicate a site of deposition below the depth of vigorous marine abrasion--about 5 fathoms. Extralimital northern species indicate a marine hydroclimate somewhat cooler than present. It is suggested that the name Elk River Beds (Diller, 1902) be restricted to underlying late Pliocene beds, rather than including the Pleistocene terrace deposits.