Joining the Hudson River to either Lake or Lake Ontario by canal was first suggested in 1699 , but work was not started until 1817 and the original canal was completed in 1825. By linking New York with the Great Lakes, the canal opened up large areas of the northern United States to settlement and farming. The original canal was 584 km (363 miles) long, 12 m (40 feet) wide and 1.2 m (4 feet) deep and ran from Albany on the Hudson River via Troy (where the Champlain Canal split off) to Buffalo on Lake Erie. Its course, which ran through the Mohawk river valley was chosen because it was the only way through the Appalachian Mountains this far north. The 183-m (600-foot) difference in height was spanned by a total of 83 locks.