Within the theoretical framework of TGG, G. H. Matthews, Chomsky's colleague at RLE, worked on the grammar of Hidatsa, a native American language.
Ethnographic accounts indicate that the Assiniboine, Sioux, Mandan, Hidatsa, Plains Ojibwa, and Atsina peoples all made use of the region for hunting or trade route purposes, though few archaeological sites have been formally identified.
He and his brother recorded the lives of three Hidatsa family members; Buffalo Bird Woman, her brother Henry Wolf Chief, and her son Edward Goodbird.
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.