The Boundary Waters Treaty is the 1909 treaty between the United States and Canada providing mechanisms for resolving any dispute over any waters bordering the two countries. The treaty covers the. Main shore to main shore of the lakes and rivers and connecting waterways, or the portions thereof, along which the international boundary between the United States and the Dominion of Canada passes, including all bays, arms, and inlets thereof, but not including tributary waters which in their natural channels would flow into such lakes, rivers, and waterways or waters flowing from such lakes, rivers, and waterways or the waters of rivers flowing across the boundary. Inter alia, the treaty guarantees that any navigable waters be "free and open."