Welcome to the Gros Ventre of Montana. The Gros Ventre, or A'aninin, are a tribe located in North Central Montana. They share the Fort Belknap Reservation with the Nakoda People, or Assiniboine tribe. To read more about the Gros Ventre tribe click here. To view pictures of the Little Rocky Mountains , click on the hyperlink. "It's good to see you". "Ne-Eh-Na-Ha-Ban"