As a result of the 1989 spring flood event on the Red River of the North, the U.S. Army Corps of Engineers, St. Paul District was tasked with evaluating a hydrologic and hydraulic computer model called UNET. The model required input data accurately positioned to within 1/10 of a foot. The Corps of Engineers contracted with the USGS to conduct a survey using the "STOP AND GO" kinematic mode. The accuracy requirement of the survey dictated that a network of reference bases be distributed throughout the study area and that shore baseline distances be maintained. The GPS survey involved making transects of over 180 miles of roads, excavation spoils banks, and over 300 individual points all with an error of less than 1/10 of a foot.