Hiráaca (also known as Hidatsa), along with the Nuue'taa (Mandan) and Apsaalooke (Crow) is a Missouri River Valley Siouan language. This branch of languages are considered part of a larger group called the Siouan Language Family. This is a big family known today to consist of more than 20 related languages (and tribal groups), all of which are considered to come from a prehistoric language that linguists & researchers call Proto-Siouan. Related languages and tribal groups also include the Dakotan (Lakota, Dakota, and Nakoda), Winnebago (Ho Chunk), and Chiwere (Ioway, Otoe, and Missouria) languages as well as the Quapaw, Omaha, Ponca, and Osage.