Iowa's SIOUX City is the fourth largest city in the state of Iowa. It is located in the northwest corner of the state, on the Missouri River. The city was founded in 1854 and has a population of 82, 684 as of 2019. It is the county seat of Woodbury County and is known for its diverse culture and history. SIOUX City is home to several museums, parks, and other attractions, making it a popular tourist destination.