Many of the items in this record group were in labeled folders or document envelopes when received; all headings were retained during processing. The series designation was determined by the storage method of the material, i.e. folders, document envelopes, or, as in the case of the timber cruises, wooden drawers.

The first series contains the correspondence of W.D. Humiston, much of whci concerns the work of the research department. The first thirteen folders were in individual file folders which were contained in a large accordion folder. The original order of the folders was maintained during processing. Folders 16 to 22 contain correspondence between Potlatch and G.J. Esselin concerning processes he was developing for Potlatch. There is some duplication of material in files 16 to 19, e.g. the original of a letter from Esselin will be in one folder, and a carbon in another. The remaining correspondence in this series concerns patents.

The second series contains other items originally foldered and includes reports, specifications for the Potlatch Mill, and a contract with the Wisconsin Log and Lumber Company, 1903.

A large portion of the material was contained in document envelopes. This material was identified by company, Potlatch Lumber Company, Washington, Idaho and Montana Railway, or other subsidiary. The material was then unfolded and placed in file folders which were then arranged alphabetically. Papers dealing with Potlatch subsidiaries, e.g. brick company, dairy ranch, etc., were arranged by company and placed at the beginning of the series. They are followed by the lumber company, and finally the railroad. Types of material include leases, deeds, rights of way, and property tax receipts and related correspondence. The final items in this series are abstracts of title.

The final series consists of timber cruise notes, or estimates of timber, in sections of Latah County. These take three forms, 5 x 8" cards, arranged by location; notebooks, identified by cruiser and also by number; and by 8 1/2 x 11" sheets of paper.