The surviving records of the Cambria Steel Company consist largely of correspondence files of the Engineering Department, ca. 1909-1923. These files (principally kept by E. T. Gray, Chief Engineer) are concerned with construction work at the various facilities in the Johnstown area. Among the projects best represented are flood control measures along the Conemaugh River, dams and pipelines for the subsidiary water companies, and war-related expansion of the various steel plants. There is also a substantial amount of material on the construction of workers' and managers' housing, particularly in the Westmont, Shady Lane, and Overbrook developments. The construction of houses and the laying-out of streets, sewers and plantings is well documented. Of special note are investigations of all-concrete houses designed by the Van Guilder Double Wall Company, Inc. The Engineering Department files also contain a small amount of information on the company's welfare work and its Cambria Library Night School and on safety meetings. There is also an incomplete series of Cost of Improvement ledgers with accounting for the many additions to the plants between 1894 and 1911.

There is also a small sample of corporate records including scattered annual reports, stockholder mailings, income statements, and a copy of the Cambria Iron Company lease. All other corporate records, including minute books, have been destroyed.

The photographs of Bethlehem plants and steel-related enterprises within Pennsylvania are composed of steel plants at Lebanon, Lehigh, Northampton, Saucon and Williamsport. There are also photographs from the Johnstown plant; this includes some early Cambria Iron Company images. These are industrial photos, as well as photographs of the community. The Johnstown material also contains thousands of glass plates negatives and forty-seven albums of company photographs made up from a selection of negatives. Most of these show steel mill construction, renovation, construction of the water supply system, homes, safety posters and devices, and first aid drills. The negatives date from 1900 to 1917. The albums are mostly composed of photographs showing Franklin Mill and open hearth and blast furnaces, Gautier mill, steel mill construction, renovation, coke plant, rod and wire mills, construction of water supply systems, safety posters and devices, and first aid drills. An oversize album of plant views (1919) drawn by commercial artist Edward Spofford (1895-1940) shows many of the Bethlehem Steel and Shipyards plants.