Water supply lakes are the primary source of water for many communities in northern and western Missouri. Therefore, accurate and up-to-date estimates of lake capacity are important for managing and predicting adequate water supply. Many of the water supply lakes in Missouri were previously surveyed by the U.S. Geological Survey in the early 2000s (Richards, 2013) and in 2013 (Huizinga, 2014); however, years of potential sedimentation may have resulted in reduced water storage capacity. Periodic bathymetric surveys are useful to update the area/capacity table and to determine changes in the bathymetric surface. Mozingo Lake and Maryville Reservoir are water supply lakes used by the city of Maryville in northwestern Missouri. The surface area of Mozingo Lake is about 1,210 acres at the flood pool level of the emergency spillway (1,065.0 feet above the North American Vertical Datum of 1988). The surface area of Maryville Reservoir is about 13.5 acres at the primary spillway elevation (1,064.3 feet above the North American Vertical Datum of 1988). No previous bathymetric surveys have been completed at these lakes. In June 2020, the U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources and the City of Maryville, completed bathymetric surveys of Mozingo Lake and Maryville Reservoir using a multibeam echosounder. Supplemental data were collected in shallow areas of Mozingo Lake using an acoustic Doppler current profiler (ADCP) mounted on a remote-controlled vessel equipped with a differential global positioning system (DGPS). The water-surface elevation on Mozingo Lake during the survey was about 1,060.4 feet, and the water-surface elevation on Maryville Reservoir was 1,061.2 feet. The echosounder data can be combined with light detection and ranging (lidar) data to prepare bathymetric maps and a surface area and capacity table for each lake. The gridded bathymetric point data for Mozingo Lake (MozingoLake2020_bathy_pts.zip) were computed on a 3.28-foot (1.00-meter) grid using the Combined Uncertainty and Bathymetry Estimator (CUBE) method, which is used as the source of points to create the bathymetric surface for Mozingo Lake. The gridded bathymetric point data for Maryville Reservoir (MaryvilleRes2020_bathy_pts.zip) were computed on a 0.82-foot (0.25-meter) grid using the Combined Uncertainty and Bathymetry Estimator (CUBE) method, which is used as the source of points to create the bathymetric surface for Maryville Lake. Bathymetric quality-assurance data for each lake (MozingoLake2020_QA_raw.zip and MaryvilleRes2020_QA_raw.zip) were collected to evaluate the vertical accuracy of the gridded bathymetric point data. Each of these four zip files contains a shapefile with an attribute table. Attribute/column labels of each table are described in the "Entity and attribute" section of the metadata file. References Cited: Huizinga, R.J., 2014, Bathymetric surveys and area/capacity tables of water-supply reservoirs for the city of Cameron, Missouri, July 2013: U.S. Geological Survey Open-File Report 2014–1005, 15 p., http://dx.doi.org/10.3133/ofr20141005. Richards, J.M., 2013, Bathymetric surveys of selected lakes in Missouri—2000–2008: U.S. Geological Survey Open-File Report 2013–1101, 9 p. with appendix, http://pubs.usgs.gov/of/2013/1101.