At the junction where the Rocky and Portage rivers join the winding St. Joseph River, the meeting of these water routes made the site a favorite Indian camping place many centuries before the coming of the white man. La Salle passed through the region in 1680 on his way east, and other Frenchmen followed, trading with the Indians. Founded in the 1830's, Three Rivers became the farthest point up the St. Joseph that large boats could reach, while flatboats and rafts carried goods to and from Lake Michigan.