The collection contains minutes, financial books, annual reports, publications, maps, miscellaneous correspondence, news clippings, photographs, timetables, and microfilmed scrapbooks. Financial records represent the largest portion of records, and there is a significant lack of executive records.

The collection contains correspondence, pamphlets, publications, minutes, press releases, one photograph, newspaper clippings, articles, maps and miscellaneous reference materials. The records reflect the organic history of the Association and the history of the entire Seaway movement from the establishment of the Association to its demise in 1939.

The collection contains correspondence, minutes, reference materials, contracts, maps, blueprints and news clippings.

The collection contains President Homer A. Massie's 1948 annual meeting address; Policies and Programs agenda, April 1948; "Report On North Shore Trip" by Minnesota Department of Business Research and Development Commissioner J. W. Clark; Minneapolis Star editorials concerning airports on North Shore, August 5 and 6, 1948.

The collection contains annual reports, 1954-1977, minutes, 1930-1977, correspondence, files by office divisions, legal materials, news clippings, publications, and photographs.

The scrapbook contains newspaper clippings pertaining to Singer’s role in the Lake Superior transportation business from 1899-1903.