Which cultural group did the hidatsa and mandan belong?

The Hidatsa and Mandan belong to the Siouan cultural group, which is a family of Native American tribes primarily located in the Great Plains region of the United States. Both tribes historically inhabited areas along the Missouri River in present-day North Dakota. They were known for their agrarian lifestyle, engaging in farming, hunting, and trade, and had a rich cultural heritage that included unique languages, traditions, and social structures.