The Tonopah Mining Company Records derive from the office of the company’s general manager in Tonopah, Nevada and consist of documents directly generated by its mining and milling operations from 1901 through 1941. The collection includes daily work reports, assay reports and certificates, employee time cards, invoices and receipts for mining equipment and supplies, monthly stores reports, and the company’s numerous insurance policies. Several of the company’s annual reports, including an original typescript copy of the 1907 annual report, are included in the collection. Additionally, select records from the company's subsidiary, Desert Power and Mill Company, as well as the Tonopah and Goldfield Railroad, which include overcharge claims, freight and repair bills, and delivery receipts are included in the collection.

The Goldfield Consolidated Mines Company Records (1904-1930) consist of correspondence, invoices, receipts with voucher checks, mining leases, insurance policies, payroll accounts, published notices and articles. Also included is a monthly Goldfield Consolidated Mines reports ledger from February 1914 to October 1916 for mines located in the south central Nevada area. The collection primarily dates from 1904, before the consolidation when the boom in Goldfield was beginning in earnest, until 1919, when the company ceased its operations in Goldfield, although there are a few records post-1919 as the company continued to exist after the mines and mill closed down.