ORWA98_750UTM is a digital bathymetric surface grid of the seafloor offthe coast of Washington and Oregon. Grid cell spacing is 750m and theprojection is UTM Zone 10.The surface grid was produced by merging National Ocean Service (NOS)Hydrographic Surveys conducted between 1926 and 1974 (primarily 1926to 1930) with recent surveys conducted by the U.S. Army Corps of Engineers(USACE) in 1998 around the entrances to Grays Harbor, Willapa Bay, and theColumbia River. The results of this work represent the best availableestimate of the seafloor morphology for the time period circa 1998. Theuser is cautioned, however, to use this data set with full knowledge ofthe original intent, the limitations, and assumptions used to generate it.