In prehistoric times, water from melting glaciers cut a wide valley between the bluffs of the Mississippi River and formed a broad flood plain where French explorers, traders, and missionaries found a large, well-established Fox Indian village. The chief's name was Alim in Indian, Chien in French, and Dog in English. Jonathan Carver visited in 1766 and called the village "Dog Plain," but its residents preferred the French name "Prairie du Chien." Peter Pond visited in 1773 and wrote that the plain was very handsome and smooth and that traders and Indians of several tribes met there in fall and spring. The United States Government later negotiated three important treaties with the Indians there in 1825, 1829, and 1830. The most important was the council that opened on August 5, 1825, when leaders of most Indian tribes of the Northwest met with William Clark and Lewis Cass for fourteen days to establish territorial boundaries for each tribe.