Hidatsa /hɪˈdɑːtsə/ is an endangered Siouan language, closely related to the Crow language. It is spoken by the Hidatsa tribe, primarily in North Dakota and South Dakota.A description of Hidatsa-Mandan culture, including a grammar and vocabulary of the language, was published in 1877 by Washington Matthews, a government physician who lived among the Hidatsa at Fort Berthold Indian Reservation.More recently, the Hidatsa language was the subject of work in the generative grammar tradition.