Erosion of riverbanks along the Missouri River is a continuing concern of many of the Tribes within South Dakota. Changing reservoir levels combined with precipitation, wind, and ice result in conditions where substantial shoreline erosion may occur within a single season. The Lower Brule Sioux Tribe’s Environmental Protection Office, in cooperation with the USGS, is using ground-based Light Detection and Ranging (lidar) to obtain precise land-surface elevation data to accurately model the erosion. Initial lidar data were collected at two locations during February and March 2011. Additional ground-based lidar data will be collected in Feb. 2012 and compared to the 2011 data to accurately document changes in the riverbanks.