Collection consists primarily of general correspondence files (1946-1957) of William M. Nichols; and subject files (1914-1966) that were maintained over the years by Harry W. Child, William M. Nichols, and John Q. Nichols. The correspondence files consist of personal letters between Nichols and a wide circle of family and friends, many of whom were also business associates. While the emphasis of the files is personal, they contain many letters concerning the operation of the various companies and concerning Yellowstone National Park management issues. The subject files contain correspondence, financial records, legal documents, and other materials organized into broad topical categories. In addition there are financial records (1914-1957) consisting principally of audit reports for several of the companies; and tax records. There are a few legal documents, and miscellaneous other records.