The USGS, in cooperation with the Shoshone-Bannock Tribes, surveyed the bathymetry of Blackfoot Reservoir in 2011 to determine temporal changes due to sedimentation and other factors, and to improve the overall accuracy of the stage-capacity table. Bathymetric surveys of high accuracy and resolution are possible through advances in instrumentation, notably a multibeam echosounder (MBES). An MBES coupled with real-time kinematic global positioning systems (RTK-GPS) has advantages over traditional techniques for surveying reservoir bathymetry, such as single-beam echosounders, acoustic Doppler profilers, or soundings, because they can provide more coverage of the reservoir bed and real-time data corrections. The topography (above-water) [...]