The Big Sioux River is a major waterway located in the Midwestern United States. It flows approximately 380 miles through South Dakota and Iowa, eventually joining the Missouri River. The river is known for its scenic beauty and diverse ecosystems, providing habitats for various wildlife species. The Big Sioux River also plays a significant role in local communities, offering recreational opportunities such as fishing, kayaking, and hiking along its banks. It serves as a natural boundary between South Dakota and Iowa, contributing to the region's geography and history. The river is an important resource for agriculture and water supply in the area.