 Idaho Falls was on its way and headed for a future that would one day see it as headquarters for an atomic energy installation; but in the year of 1900, it was still a city under the control of Blackfoot.Blackfoot was the county seat of Bingham County which still harbored Idaho Falls and it was to be 11 years before Idaho Falls became the county seat.According to the U.S. Census Bureau, the county has a total area of , of which is land and (1.8%) is water.