Omaha is a city located in the state of Nebraska on the Missouri River. It has five letters and is the largest city in the state. Pierre is a city located in South Dakota on the Missouri River. It has six letters and is the state capital. Osage is a city located in Iowa on the Missouri River. It has five letters and is the county seat of Mitchell County. Otoe is a city located in Nebraska on the Missouri River. It has four letters and is the county seat of Otoe County. Platte is a city located in South Dakota on the Missouri River. It has six letters and is the county seat of Charles Mix County. OmahaNebraska is a portmanteau of Omaha and Nebraska, and has thirteen letters. It is the name of a city located on the Missouri River that is a combination of the two states.