Besides its far-flung “empire” of island territories and possessions distant from its mainland, the United States includes a large number of relatively nearshore islands off its several coasts. Of course, our two youngest states, Alaska and Hawaii, are totally separate from the Lower 48, but today’s subject is not so obvious. The area in question isn’t along our southern border, where the Rio Grande defines much of Mexico’s extent. When that river jumps its banks and carves a new path, it creates what are called pene-enclaves, and both governments look the satellite images and maps over and sign off on the new facts on the ground. Sometimes it’s a few new sandbars for us, sometimes it’s a little for them. This process gets in arrears as the Rio Grande is constantly shifting, but there is an understanding of the situation. There is also a place in the waters between Alaska and Canada called Nunez Rocks. They only surface at mid-tide or lower, but due to the complicated interpretation of borders and maritime law, it hasn’t been totally settled whether the rocks belong to the US or Canada.
These are shifting or as-yet-unjudicated situations. Our subject here is long-settled law along the Canadian border, but you could spend many hours with a map of the United States and not notice that there are a couple of pieces of the US up along the northern border that are not attached. Many people have never even heard of them, but they’re favorites among geographers due to their quirky locations and history.
The story of the Northwest Angle goes all the way back to the original legal agreements that established our country. In 1783, the Treaty of Paris was the formal understanding that we were free of England and there was now a line to be drawn between the US and Canada, which was still British territory. That line would of course begin at the Atlantic Ocean and run westward, eventually along a path that would split most of the Great Lakes, and go on to the Mississippi River. Just beyond Lake Superior, the border would follow the center of watercourses and lakes that led to Lake of the Woods, north of what is now Minnesota. At the northwesternmost point of that fairly substantial lake, the line would proceed directly west to the Mississippi.
It all sounds pretty straightforward, but it presupposed some geography that didn’t exist. The best maps of the time depicted Lake of the Woods as a roundish basin with a fairly even shore. No problem was seen in establishing the proper point from which to proceed. But in reality, the lake isn’t the least bit regular in shape, having all sorts of inlets and bays, so that identifying the northwesternmost extent of it was not at all obvious. Even if that point was settled, the rest of the survey directions were even more unusable because the entirety of Lake of the Woods is north of the origin of the Mississippi, and so no line going directly west from it could intersect the river. Such was the state of mapping in those days, and only laborious overland observations could reveal the actual facts. By 1798, a British explorer had determined that the lake in question was indeed too far north, and the line therefore not feasible.
In 1803, the United States made its best investment to date: the Louisiana Purchase. France handed over a huge and loosely defined tract of land, where the Mississippi River and the Gulf of Mexico were the only hard-and-fast borders. Neither buyer nor seller knew exactly what lay out west, or up north. By 1807, the British and Americans were at work on settling the northern border of the Purchase, with the British suggesting the 1783 water-guided line should proceed until it intersected the 49th parallel, and thence westward. Wishing to maintain the wording of the original treaty, the Americans balked. Negotiations went back and forth for some time, but in the Convention of 1818, it was decided that from that nebulous “northwesternmost point of Lake of the Woods,” the line would indeed head to the 49th parallel and then west.
Even at this late date, there was no solid knowledge of the shape of Lake of the Woods, nor its position in relation to latitude 49 degrees north. British surveyors went to work on the lake, and by 1824 had found no fewer than four possible “northwesternmost” points. Further work singled out a point at the top of Angle Inlet as the place from which to make the angle to the 49th parallel. In 1842, the two sides agreed to accept that. The line to the parallel then had to proceed south for the intersection to be made. In so doing, it cut right across a peninsula poking into the lake that by logical design should have been part of Canada. No part of it connected by land to the US. Canada and Great Britain tried to negotiate a more advantageous position, and even offered to buy the odd bit of land outright, but the US wouldn’t budge from the language of the 1783 treaty. The arrangement was sealed in the Webster-Ashburton Treaty of 1842, and the Northwest Angle, as it came to be known, became American land. So too, did two much tinier bits of land that the 49th parallel sliced off the tips of points in the Lake of the Woods: Elm Point, and Buffalo Bay Point. Altogether, Canada lost out on a mere 123 square miles, more or less in the middle of nowhere.
In 1846, the US and Britain settled out the westernmost stretch of the Canadian border through the Oregon Treaty. It maintained the frontier along the 49th parallel, until it reached the Pacific coast just east of Vancouver Island. Along the convoluted coastline, however, another peninsula, Point Roberts, pokes southward from Canadian land and dips below the boundary. Once again, the sliced-off bit of land, not quite five square miles, went to the US. Like the Northwest Angle, it can only be accessed directly from the US by boat—by road, one has to pass through Canada.
These odd bits of the US are called exclaves. They are similar to the more familiar enclaves, but enclaves are countries or parts of countries entirely surrounded by another. Since the Northwest Angle and Point Roberts can be accessed by water, they are not true enclaves. By any name, such peripheral chunks of land make great trivia questions, and are intriguing little nuggets of geographic history.
Be one of the few who can say they’ve been to the Northwest Angle! This Delorme Atlas of Minnesota will get you up to Lake of the Woods—then you’ll need a boat or a passport. Have fun!