This dataset contains digital elevation models (DEMs) for four reaches of the Big River in Missouri. The study reaches are as follows: Site W (STW), Rockford Beach (RFB), Phelps Bend (PHB), and Washington State Park (WSP). The reach DEMs were created in support of research assessing the hydraulic conditions of freshwater mussel habitat in the Big River. Channel and bank elevations were generated from data collected by USGS staff from the Columbia Environmental Research Center between February 2019 and January 2020 using single-beam echosounder surveys, manual Global Navigation Satellite System (GNSS) topographic surveys, and terrestrial light detection and ranging (lidar) surveys. Elevations for areas beyond the active channel were generated from Missouri aerial lidar data collected between December 2010 and April 2011 by the Surdex Corporation for the U.S. Army Corps of Engineers St. Louis District. Prior to DEM generation, elevations were locally smoothed to remove small tributary drainages that would lead to erroneous water routing during modeling.