<span>The treaty was signed on June 15, 1846,
ending the joint occupation with Great Britain and making most
Oregonians below the 49th parallel American citizens. ... When the
Colony of British Columbia joined Canada in 1871, the 49th Parallel and
marine boundaries established by the Oregon Treaty became the Canada–US border.</span>
Geographic means physicals features of the land in this case you look at only the negatives of this like big bodies of water mountains and steep terrain these made it difficult because some settlers didn't have horses or were traveling in large groups wich could contain elderly and young children
