The Ambergris has been organized into six series: Records of the Board of Directors, General Correspondence, Capitol Stock Records, Financial Records, Tax Records, and Personnel Records.

The first series, Records of the Board of Directors, contains minute books from all three phases of the company's history, and records related to meetings and reports from the final phase. Included are, notices of meetings, copies of by-laws, lists of stockholders, records of elections, records of assessments, and some correspondence. Arranged chronologically by meeting.

The second series consists of a correspondence file, organized chronologically, and an alphabetically organized file of general records.

The correspondence file, 1901-1929, contains records of the Ambergris Mining Co. and the Ambergris Mines Co., chiefly concerning capital stock matters and including correspondence regarding issuance of shares, transfer of shares, and assessments, supplemented by lists of stockholders, lists of delinquent stock, receipts for certificates issued, assessment notices, assessment receipts, and a few legal documents relating to the probate of the estates of various stockholders. For the years 1916-1917 there are a great many letters from stockholders authorizing the exchange of shares in Ambergris Mining Co. for stock in any new corporation that may be formed, directing the exchange of Ambergris Mines certificates for Ambergris Mining certificates, or enclosing payment for the initial assessment against Ambergris Mines stock. There are also many Ambergris Mining Co. certificates, bills and receipts for supplies and services required in the reorganization, and an undated memorandum by Harry Day explaining the reasons for forming the new company. The folder for 1929 contains an Ambergris Mines dividend list dated Feb. 18 of that year.

In addition to stock-related material there are receipts for expenses; balance sheets; a trial brief, ca. 1901, concerning the case of Ambergris Mining Co. vs. Harry Day; location notices from 1901, 1903, and 1918; copies of the minutes of the board of directors' meetings of Apr. 10, 1908 and July 7, 1917; an indenture relating to transfer of property from Ambergris Mining Co. to Ambergris Mines Co., Dec. 14, 1916, and a draft of the same; an agreement between Ambergris Mines and Providence Hospital, Dec. 27, 1917; signed proxies and other records relating to annual meetings, especially in 1924, 1925, 1928, and 1929; and ore settlements for sales to the Hercules Mill, 1927. For many years there are Annual Statements of Domestic Corporations, Annual Statements or Annual Reports to the State of Idaho, federal Capital Stock Tax Returns, Corporate Income Tax Returns, and Shoshone County tax receipts.

Included in the general records, 1925-1940, are: correspondence; letters of transmittal; telegrams; legal documents such as certificates of incorporation, affidavits of improvements, indentures, leases, and probate court records; notices of meetings; notices of dividends; dividend checks; statements of account with the Hercules Mining Co.; assay certificates; annual reports to the Idaho Department of Mines; financial statements; annual reports to the U.S. Bureau of Mines; annual reports from the manager (Henry Day) to the president (Jerome or Harry Day); papers filed with the Securities and Exchange Commission and the Seattle and Spokane Stock exchanges; lists of stockholders; lists of equipment and supplies; ore settlements; and other records.

The largest part of this material concerns capital stock matters: issuance and transfer of certificates, delinquencies in assessment payments, and dividends. There are also records concerning incorporation of the consolidated company and the liquidation of the Ambergris Mines and the Guelph Mining and Milling companies. There is a good deal of material on operations, including claim location and assessment work, progress in development, ore production, wage scales, and safety practices. One file of Miscellaneous Legal Documents precedes the alphabetical sequence, and two files concerning the final liquidation of the Ambergris follow the sequence.

Correspondence in the latter chiefly concerns the surrender of certificates and payment of the final liquidating dividend. Many legal documents relating to the probate of stockholder's estates are included. There is also a list of equipment stored at the Hercules Mining Co.

The third series includes capital stock records from all phases of the company's history, from creation to liquidation.

The fourth series, accounting records, contains only ledgers and journals from the latter two phases of the company's existence.

The tax records of the fifth series, 1929-1940, reflect only the activity of Ambergris Consolidated. Included are federal and state tax records; claims for refunds or abatements; capital stock tax returns; legal briefs, claims, answers, lists of cases, correspondence, and other court documents; State of Idaho corporate tax returns, annual statements of domestic corporations, and annual statements. Much of this series relates to Ambergris Consolidated Mining Co.'s successful contention that it had not been doing business within the meaning of the federal capital stock tax law.

The final series contains the only record of personnel in this group, a binder of daily work reports.

Removal of cancelled and unissued stock certificates, assessment receipts, returned notices of meetings, vouchers, paid checks and bank statements, check stubs, and duplicate materials reduced the bulk of this collection by 6.5 cubic feet.