Home > Listings > Duluth Seaway Port AuthorityDuluth Seaway Port Authority 802 Garfield Avenue, Duluth, Minnesota 55802(218) 727-8525 https://www.duluthport.com View Map Duluth-Superior is a diversified multimodal shipping hub, offering global cargo transport through the Great Lakes-St. Lawrence Seaway, free-flowing major highways and direct Class I rail service to the East, West and Gulf Coast.