The Copper Range Motor Bus Company Records consist primarily of financial records but also include minutes of stockholders and board of directors meetings and some employee records and correspondence. Additional documentation can be found in the Copper Range Railroad Company Records (Subseries IV).

This subseries contains general medical records, including logbooks kept by company physicians and by Trimountain Hospital.

This subseries contains general medical records, including logbooks kept by company physicians and by Trimountain Hospital.

This subseries contains general medical records, including logbooks kept by company physicians and by Trimountain Hospital.

This subseries contains general medical records, including logbooks kept by company physicians and by Trimountain Hospital.

This subseries consists of injury records from Baltic Mine and Baltic Mill. Surgeon's reports and injury reports are filed by employee number when given. Reports without employee numbers are filed by occupation. Reports to the Michigan Industrial Accident Board are filed alphabetically.

This subseries consists mostly of financial records from the Boston Office (moved to Portland, Maine in 1920) but also includes meeting records and maps.

The President's Office Records include correspondence and chronological files, as well as records of labor disputes and the abandonment, dissolution, and liquidation of the Copper Range Railroad Company.

Most of the records are from Presidents William H. Schacht and William P. Nicholls, as well as additional material from Secretary Florence E. Gregorich. The non-railroad records from Schacht and Nicholls can be found in Series VIII, Subseries IV-V.

This subseries contains the records of small companies unconnected with the Bigelows or St. Mary's. Most of the companies were affiliated with Paine, Webber & Co. Especially of note is the minute book of the Woodstock Corporation, which provides a window onto the speculative activities of the Paines and their associates.

This subseries contains court documents, correspondence, and reports relating to the bankruptcy and reorganization of the Copper Range Railroad Company. Unless otherwise noted, the files are from General Counsel H. C. Schulte (for Schulte's non-railroad files, see Series II, Subseries X).