Data release doi:10.5066/P9RIB5GC associated with this metadata record serves as an archive of single-beam bathymetric (SBB) data collected in July 2004 (Madison Bay) and August 2008 (Bully Camp, Point au Chien, Caminada, Fourchon, and Leeville) at six study areas in the Mississippi River Delta Plain (MRDP), Louisiana. Data were collected from historically formed open-water bodies as part of the U.S. Geological Survey’s (USGS) Gulf Coast Subsidence project to provide more extensive spatial coverage than water depths collected only along coring transects in 2002, 2003, 2006, and 2007 (USGS Open-File Reports [OFR] 2005-1216 and 2009-1158). The bathymetric data were used to estimate magnitudes of one-dimensional (vertical) and three-dimensional (volume) accommodation that formed as a result of extensive historical wetland loss in Barataria and Terrebonne Basins in the MRDP. All bathymetric data are provided as x,y,z point data in the projected coordinate system North American Datum of 1983 (NAD83), Universal Transverse Mercator (UTM) Zone 15 North (15N) and all elevations are North American Vertical Datum of 1988 (NAVD88) orthometric heights, derived using the GEOID03 geoid model.