The coastal portion of the Pacific Northwest of the United States, the states of Washington and Oregon, involves 2,800 mi fronting on the Pacific Ocean, ocean estuaries, the Straits of Juan de Fuca and Georgia and Puget Sound and its adjacent waters. Ocean coastal areas are characterized by bold, rock headlands and elevated marine terraces with intervening drowned estuaries guarded by bay mouth spits and bars. The Columbia River is the only stream of continental proportions which exits in this segment of coast line. Engineered works for navigation improvement began in the mid 1880's and has continued to the present time. Twentieth century commercial and residential development of coastal areas with attendant transportation networks and ground-water supply have required solutions to land use, erosion and construction problems.