The coastline near the Columbia River, between Tillamook Head, Oregon and Grays Harbor, Washington, is characterized by prograding beaches in contrast to the rest of the WashingtonOregon coast where actively eroding sea cliffs are present. The Columbia River appears to be the major contributor of sediment to the beaches and probably accounts for their prograding character. Littoral transport of material from coastal erosion probably has some effect on the sediment budget, but coastal barriers of promontories and estuaries limit influx of this material. Some material is added to the beach as a result of jetty breakdown, especially near Grays Harbor, Washington. Willapa Bay apparently contributes only minor amounts of sediment to the area. The net direction of beach sediment movement near the Columbia River appears to be northward. Seasonal changes in the direction of wave attack complicate the analysis, but the greater energy associated with winter wave conditions is directed northward and probably results in a predominant northerly sediment movement. Mechanical and heavy mineral analyses are consistent with the results of wave studies.