Mackenzie, Alexander. "A map of America between latitudes 40 and 70 north and longitudes 45 and 180 west, exhibiting Mackenzie's track from Montreal to Fort Chipewyan & from thence to the north sea in 1789 & to the west Pacific Ocean in 1793." Map. London: Alexander Mack Kenzie, 1801. Norman B. Leventhal Map & Education Center, https://collections.leventhalmap.org/search/commonwealth:8049g9163 (accessed April 19, 2024).