A granite obelisk one mile west was the first of a series of similar markers along the 49th parallel, defining the Canadian-American line from the Strait of Georgia to the summit of the Rocky Mountains. The official survey, begun at Point Roberts in 1857, was a joint venture by American and British boundary commissions. Completed in 1862, it carried out provisions of the treaty of Washington of June 15, 1846, and virtually ended the old dispute between Great Britain and the United States over sovereignty in the Pacific Northwest.