The collection contains records of Clyde Iron Company (1889), Northwestern Supply Company (1899), Northwestern Manufacturing Company (1899), Clyde Iron Works, Cleveland Duluth Company, Inc. (1920), Willamette Clyde Company (Oregon, 1923), Cleveland Duluth Holding Company of Minnesota (1926) and Clyde Iron Works Sales Company (renamed Clyde Sales Company) the sole distributor for Clyde Iron Works. There are no records of the Clyde Equipment Company.

The collection holds: Articles of Incorporation with amendments June 1933, September 1947; By-laws 1943, September 4, 1947, December 31, 1957; purchase agreement by General Waterworks Corporation of Delaware, 1962; Financial records 1932-1958; Reincorporation under Minnesota Laws; Stockholders 1933, 1956, 1962; Reports to city of Duluth 1942-1979; Minutes volume 1929-1933 and 1942-1957

The collection consists of certificates of incorporation and by-laws and a history of the company; minutes 1908-1910; titles, leases, deeds 1887-1959; contracts, correspondence and minutes; stock ledgers 1902-1913; financial statements and balance sheets 1919-1944, 1945-1957; personnel 1956; appraisal 1917; and one black and white photograph of the buildings.