From 1946 to 1966, the government constructed the Fort Randall and Big Bend Dams as flood control projects on the Missouri River in South Dakota. The reservoirs created behind the dams flooded about 38,000 acres of the Crow Creek and Lower Brule Indian reservations. The tribes received compensation when the dams were built and additional compensation in the 1990s. The tribes are seeking a third round of compensation based on a consultant's analysis. The Congress provided additional compensation to other tribes after two prior GAO reports. For those reports, GAO found that one recommended approach to providing additional compensation would be to calculate the difference between the tribe's final asking price and the amount that was appropriated by the Congress, and then to adjust it using the inflation rate and an interest rate to reflect a range of current values. GAO was asked to assess whether the tribes' consultant followed the approach used in GAO's prior reports. The additional compensation amounts calculated by the tribes' consultant are contained in H.R. 109 and S. 374.