NOTE: These data pertain only to the two U.S. locks (Snell and Eisenhower) on the Saint Lawrence Seaway between the Port of Montreal and Lake Ontario. Canada operates another five locks along this portion of the Seaway, as well as other Seaway locks.
SOURCE: U.S. Department of Transportation, Saint Lawrence Seaway Development Corporation (SLSDC), Annual Reports (Washington, DC: various years). Reports for years 1997–2001 available at http://www.greatlakes-seaway.com/en/aboutus/slsdc_annrept.html, as of March 2004. 2002— SLSDC, personal communication, March 2004.