Duluth, Minnesota at the western end of the Saint Lawrence Seaway, the Duluth–Superior seaport is the largest and farthest-inland freshwater seaport in North America. By far the largest and busiest on the Great Lakes, the port handles an average of 46 million short tons of cargo and over 1,100 visits each year from domestic and international vessels. With of waterfront, it is one of the leading bulk cargo ports in North America and ranks among the top 20 ports in the United States. Duluth is a major shipping port for taconite pellets, made from concentrated low-grade iron ore and destined for midwestern
Lake Duluth not been determined. It is known, however, that the lake extended at least to the Kaministiquia River basin west of Fort William, Ontario. It is probable that there was a protrusion of the ice into Keweenaw Bay at the time of greatest expansion of Lake Duluth, and the east end of the Keweenaw Peninsula may have been beneath the ice down to the time the Lake Duluth waters were drained eastward. Glacial Lakes in the Lake Superior basin Lake Duluth Lake Duluth was a proglacial lake that formed in the Lake Superior drainage basin as the Laurentide ice sheet retreated.