The North-West Mounted Police (NWMP) also used the trail in their March West in 1874.
[1][2] American and Canadian surveyors worked together in the difficult task of surveying the border, which was agreed upon in the Treaty of 1818 to be the 49th parallel.
They met in September 1872 in Pembina, Dakota Territory, where they spent the winter before heading out in the spring of 1873 to begin surveying and placing markers along the route starting at the Lake of the Woods.
In the spring they continued their work and the last marker was placed on 8 August 1874 at Waterton Lake.
Waterton Lake straddles the 49th parallel in present-day Alberta and Montana.