 Beginning in the 1820s , a fur trading route developed between the Red River Colony ( in modern Manitoba ) and the trading posts in Minnesota , first primarily at Mendota and later at Saint Paul . The system of <unk> cart trails came to be known as the Red River Trails and was used principally by the Métis as a way to avoid the fur trade monopoly of the Hudson 's Bay Company ( which had absorbed the North West Company ) . Though this cross @-@ border trade was entirely illegal and violated the policies of the Hudson 's Bay Company , enforcement against the trade by American and British authorities was virtually non @-@ <unk> . The trail system would reach its peak usage in the mid @-@ 19th century . The Hudson 's Bay Company continued to expand its presence north of the U.S. border establishing new posts such as Fort Alexander and Rat Portage . 
