H067
Where in the U.S. can you only drive to through Canada?
Two places: the Northwest Angle in Minnesota and Point Roberts in Washington. The border cuts both off from the rest of the country, so every drive home means crossing into Canada and back.
The Northwest Angle, MinnesotaCut off by a mapping mistake
Point Roberts, WashingtonCut off by a straight line applied exactly
These two exclaves look alike, but one came from a wrong map and the other from a right one. The Northwest Angle exists because the 1783 treaty's negotiators thought the Mississippi started north of Lake of the Woods; the 1818 fix left a patch of Minnesota stranded. Point Roberts is exactly where the 1846 Oregon Treaty put it: the 49th parallel ran straight across a peninsula and left its tip American.
The same odd result can have opposite causes, so check the history before assuming a mistake. Borders and rules preserve what their authors believed, and a simple rule applied everywhere will eventually produce a strange case somewhere.
Try it somewhere else
Hyder, Alaska, has no road to the rest of Alaska. You can only drive there through Canada.
Was Hyder cut off by a mistake, a rule, or the land itself?
The Northwest Angle: a border drawn from a bad map
The 1783 Treaty of Paris described a line that couldn't exist. It ran the border to "the most northwestern point" of Lake of the Woods and then due west to the Mississippi River. The negotiators were working from the 1755 Mitchell Map, which drew the lake as a simple oval and put the Mississippi's source far to the north. In 1797 the surveyor David Thompson showed the river actually starts well south of the lake — so a line due west from its northwest corner would never reach the Mississippi at all.
The fix created the notch. The Anglo-American Convention of 1818 patched the gap by running the border from that northwesternmost point due south to the 49th parallel, then west along it. Surveyors fixed the point at Angle Inlet in 1825, and the Webster–Ashburton Treaty of 1842 confirmed it. Everything north of the 49th parallel and east of that due-south line — a patch of forest and islands cut off from Minnesota by Lake of the Woods — stayed American.
Living with it: the only road in runs through Manitoba, so every drive to the Angle means leaving the U.S. and coming back. There's no staffed U.S. border station at the Angle. Travelers check in with U.S. Customs and Border Protection by video at an unstaffed kiosk at Jim's Corner, or at a couple of local marinas. In summer, boats cross Lake of the Woods directly; in winter, a plowed ice road sometimes does. For most of the year, though, the only way to drive to this part of Minnesota is through another country.
Point Roberts: a straight line, followed exactly
The line is exactly where it was meant to be. The Oregon Treaty of 1846 extended the U.S.–British border west along the 49th parallel to the Pacific coast. That clean, straight line happens to cross the base of a small peninsula hanging down from what is now Delta, British Columbia, leaving its southern tip on the American side. The British government saw the problem and later told its boundary commissioner to ask for Point Roberts, offering a small adjustment to the line elsewhere in exchange. No deal was ever made, and the tip stayed American.
Living on the wrong side of the line: Point Roberts has one doctor's clinic but no hospital, dentist, pharmacy, or veterinarian, so residents usually drive through Canada to Bellingham for care. Kids go to the local primary school through 3rd grade. From 4th grade on, they ride a bus about 40 minutes through British Columbia to school in Blaine, crossing the border four times a day. In summer the population swells to about 4,500, mostly Canadians with vacation homes.
Not the only ones: Elm Point, a sliver of Minnesota just south of the Angle, can also be reached by land only through Canada.
Related exhibits
Sources: Northwest Angle: Wikipedia, "Northwest Angle" (2020 population of 149 and land and water area for Angle Township; northernmost point of the contiguous U.S. at 49°23′24″N, 95°09′11″W; the ~63-mile (101 km) route via MN Highway 313, the Warroad–Sprague crossing, Manitoba Highway 12, and Provincial Roads 308 and 525; customs check-in at Jim's Corner; and the 1783, 1797, 1818, 1825, and 1842 border history); Wikipedia, "Manitoba Provincial Road 308" and "Manitoba Provincial Road 525"; Britannica, "Why Does Minnesota Have the Northwest Angle?" Map from Natural Earth 1:10m data (states and provinces, lakes, borders, and roads); the route through the Manitoba forest is simplified. Point Roberts: Wikipedia, "Point Roberts, Washington" (2020 population of 1,191; land area 4.884 sq mi (12.65 km²); summer population of about 4,500; the ~25-mile (40 km) route through Canada; schooling, medical services, and the British request to acquire Point Roberts after the 1846 Oregon Treaty); Wikipedia, "Point Roberts–Boundary Bay Border Crossing" (westernmost land crossing in the contiguous U.S.). Map: coastlines from OpenStreetMap land polygons (© OpenStreetMap contributors, via the geo-maps project at 100 m resolution); border and highway lines from Natural Earth 1:10m data. The route follows 56th Street, then BC Highways 17 and 99, to the Peace Arch crossing.