Council Bluffs is a city in and the county seat of Pottawattamie County, Iowa, United States. It is the most populous city in Southwest Iowa, as well as the third largest and a primary city of the Omaha-Council Bluffs Metropolitan Area. It is located on the east bank of the Missouri River, across from Omaha, Nebraska. Until about 1853 Council Bluffs was known as Kanesville. Kanesville was the historic starting point of the Mormon Trail.