49th parallel

Line of latitude that forms the western part of the border between Canada and the USA. Extending west from the Lake of the Woods to the Pacific, it was laid down by treaties concluded in 1818 and 1846. Most Canadians actually live south of the 49th parallel, in Ontario, Québec, and the Maritime provinces.

The western end of the 49th parallel cuts through the Point Roberts Peninsula; the north of this promontory lies in British Columbia, while the south is in Washington State, but unconnected to the US mainland. Beyond this, the border was made to dip south of the Parallel, through Juan de Fuca Strait, to satisfy British demands for sovereignty over the whole of Vancouver Island. When establishing the border, in order to mark it accurately on the ground, surveyors took star sightings on a succession of points on the horizon, between which they then drew a line. This subsequently served as a line of origin for the series of surveyors' base lines that were used to determine the boundaries of Canada's Prairie Provinces. The frontier is defined in some places by open ditches, and in others by clearings through stands of timber.