Lake of the Woods

Lake of the Woods

Drawing the Line… The Canada-U.S. Border


A general rule of thumb when establishing a boundary is to know the lay of the land in question. If one does, chances are the boundary will make sense, it will be geographically sound, and once established that will be it.

When the Canada-US boundary west of Lake Superior to Lake of the Woods was first established in 1783, those involved in the negotiations hadn’t a clue about the lay of the land. The result? Almost another 60 years of squabbling and a boundary that has been described as “irrational and impractical” and, at one point, geographically impossible. Today when one looks at a map, the border between Canada and the United States follows a seemingly logical route from the east coast through to the west coast except for the bizarre little jog it takes into Lake of the Woods.

Boundary discussions began in 1783 with the signing of the Treaty of Paris which ended the American Revolution. In acknowledgement of American independence, a boundary was established between the United States and the British territory to the north. The general plan was to have the boundary begin at the Bay of Fundy and extend west to the Mississippi River.

The maps of the day were based on the observations and sketches of explorers and fur traders which were essentially tracings of canoe routes that contained only the necessary information for navigating. However, lack of information and uncertainty didn’t deter the map-makers of the day.

John Mitchell, a cartographer for the Lord Commissioner of Trade and Plantations, had published a map of the British and French Dominions of North America in 1755 and it was this map that was used to establish the boundary west of Lake Superior through to Lake of the Woods. Mitchell’s map had its shortcomings, not the least of which was its alarming inaccuracies. For instance, Lake of the Woods was depicted as a perfectly ovoid-shaped lake with nine islands. More importantly though was a small note in the upper corner of Mitchell’s map – “The head of the Mississippi is not yet known. It is supposed to arise about the 50th degree of latitude.” Assuming that a due west line would strike the Mississippi, the treaty commissioners described the boundary as running west from Lake Superior to the northwesternmost point of Lake of the Woods and then due west to the Mississippi.

Discovery of the geographical impossibility of the boundary didn’t come to light until 14 years after the signing of the Treaty of Paris. In 1797, explorer, map-maker, and North West Company employee David Thompson located the most northerly source of the Mississippi a few miles north of Bemidji, which is south of Lake of the Woods.

The British proposed another look at the boundary. The Americans, realizing that the error had been in their favour, weren’t interested. Even when the 48th parallel came into play as the northern boundary of the United States after the Louisiana Purchase of 1803, the Americans still insisted on the inclusion of the northwesternmost point of Lake of the Woods (which is north of the 49th parallel) as a reference point in the boundary settlement.


The boundary wasn’t looked at again until 1814 with the signing of the Treaty of Ghent at the conclusion of the War of 1812. Again the British suggested revising the boundary to run west from Lake Superior directly to the headwaters of the Mississippi (at Lake Itasca in Minnesota and well south of Lake of the Woods), ceding them more territory than the original agreement. The Americans remained adamant. They would agree to a re-examination of the boundary from Lake of the Woods to the Mississippi only.

The result of that treaty was that in 1818 both governments agreed that the border would run from the mouth of the Rainy River by a direct line to 100 yards east of Oak Island and then to the northwesternmost point of Lake of the Woods and from there in a north or south direction (“as the case may be”) to the 49th parallel and then due west along the parallel.

The next step was to determine the exact location of the northwesternmost point of Lake of the Woods. A survey team was sent out in 1822 and returned red-faced and unsuccessful. They had been completely baffled by all the islands, bays and peninsulas and claimed that determining the point was an impossiblity.

In 1824, the Commission hired David Thompson to determine which point would be used. He returned to them with four possible sites – one in Northwest Angle Inlet, one in Monument Bay, a third in Portage Bay, and the fourth at the north end of the lake, near the portage into the Winnipeg River. Either the most western or the most northern point would have to be chosen – Northwest Angle or Rat Portage (now the city of Kenora).

The following year, Dr. J.L. Tiarks, an astromoner with the British government, conducted an inspection of both sites and determined that the Northwest Angle was the most northwestern point on the lake. From that point, a perpendicular was dropped to the 49th parallel, just above Muskeg Bay, creating the Northwest Angle.

In 1842, with the signing of the Webster-Ashburton Treaty, the boundary between Lake Superior and the 49th parallel was finally settled.

It took nearly 60 years to roughly establish the boundary that runs through Lake of the Woods. It was another 60 years before the line was properly surveyed, mapped, and monumented. Until then there still arose questions about the nationality of certain islands on the lake.

The Treaty of 1908, concerning the boundary between Canada and the United States from the east to the west coast, stipulated that there needed to be a re-establishment of the international boundary in which the course of it was described in detail and marked with boundary reference markers.

From 1912 to 1916, survey crews from both Canada and the United States worked along the boundary from Lake Superior west through Lake of the Woods. Reference boundary markers were erected, triangulation towers were built, and exact geographical reference points were taken. The surveying and mapping was completed in 1916. During that period, surveyors set 1382 monuments along the 426 miles of boundary line, determined 5100 reference points, and surveyed 1740 square miles of territory to produce 36 joint boundary maps.

Even still, things weren’t completely settled. Another treaty in 1925 was struck to more clearly define the boundary and to maintain the demarcation of the line. The northwesternmost point of Lake of the Woods was adjusted a final time.

Here’s to that eccentric boundary that was one hundred and forty-years in the making. It was drawn and redrawn but still includes that odd little jog that splits Lake of the Woods between two countries, creates the American orphan-land of Northwest Angle, and absolutely defies logic.

By Lori Nelson