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Russell L. & Lyn Wood Mining History Archive

Robert D. Hoffman Collection

This Collection (1917-1977) focuses on the working papers of Robert Hoffman, mining engineer and geologist. It includes documents, correspondence, reports and field journals, but also scattered photographs and personal materials. Sketch portrait of Robert Hoffman with pipe

Group photo including Robert Hoffman

Hoffman started his career during the 1920's Canadian "gold rush" as a young man, and worked other sites in Canada including the Sunset Yellowknife mines, Northwest Territories. He invested in or owned a number of mining companies in both the US and Canada, and was president of Quebec Cobalt Mining and Exploration Ltd. and Towne Mines Inc. Hoffman gifted Harvard University with the David and Arnold Hoffman Memorial Building for Experimental Geology in honor of two brothers.

Hoffman's portrait, Irwin Hoffman Collection A0069.

Noted in the Collection:

  • Correspondence as a student with Louis Caryl Graton, a leading figure in the study of ore deposits.
  • Autobiographical account of Hoffman's experiences in Rouyn, Canada.
  • Documents, Sunset Yellowknife Gold Mines, Limited: Includes operational documents and maps, assay data, camp inventories.

Related Resources

Geographic Areas & Companies of Interest


  • Dairy Farm Mine, Placer County, CA
  • Palm Wash Calcite mines, Indio, Riverside County, CA
  • Walker Lease, Cripple Creek, Teller County, CO
  • Emma Nevada Mine, Kimberly, White Pine County, NV
  • Esterly Mine, Waldo district, Josephine County, OR

field notebooks


  • Amalgamated Silver Mines Company (Montana)
  • Calcite Operators, Inc. (California)
  • Calumet & Hecla Mining Company (Michigan)
  • Consolidated Coppermines Company (Nevada)
  • Gold Operators, Inc. (Oregon)
  • Mesabi Iron Company (Michigan)
  • Waldo Consolidated Gold Mining Company (Oregon)


  • Sunset Yellowknife mines, Sunset Lake, Yellowknife, Northwest Territories, Canada
  • Rouyn (Rouyn-Noranda), Quebec, Canada
  • Belleterre, Temiscamingue Regional County Municipality, Quebec, Canada
  • Temagami, Quebec, Canada
  • American Metals Company claims, Duprat Township, Quebec, Canada
  • Smith Cobalt mines, Temiskaming district, Ontario, Canada
  • Cabot Township, Sudbury district, Ontario, Canada
  • Groves Township, Sudbury district, Ontario, Canada
  • Connaught Township, Sudbury district, Ontario, Canada
  • Saville claims, Onaping region, Ontario, Canada


  • American Metals Company
  • Bidgood-Kirkland Gold Mines
  • Gold Operators (Canada) Ltd.
  • Gordon Lebel Mines Ltd.
  • Quebec Platinum Mines Ltd.
  • Quebec Cobalt and Exploration Ltd.
  • Slate Islands Mining Company
  • Smith Cobalt Mines, Ltd.
  • Sunset Yellowknife Mines Ltd.
  • Yellowknife Gold Mines Ltd.


Box 1 -- Miscellaneous documents, photographs and correspondence related to Hoffman's education and career; Sunset Yellowknife Mines Limited documents (1917-). Includes:

  • Photographs and postcards of Hoffman's travels; Hoffman's diary, "The Rouyn Rush" (1922-1923).Front page, Yellowknife Blade newspaper
  • Correspondences related to the minerals industries: Louis C. Graton; McGeorge Bundy; Christien A. Herter.
  • "The Bushwackers," a manuscript of a musical play by Arnold Hoffman about prospectors in northern Canada.
  • Maps, diagrams and assay information for the Sunset Yellowknife mines; Alice group of mines and related properties
  • Documents and correspondence on the mine buildings, equipment and operations; Sunset Yellowknife Gold Mines Limited  company documents (1938-1949)

Box 2 -- Materials from Hoffman's early career; operational documents, maps, diagrams and correspondence from mining operations in which Hoffman was involved (1921-1965). Includes:

  • Materials related to Hoffman's early activities after graduating from Harvard (1921-1924)
  • Calumet & Hecla Mining Company (1920s)
  • Smith Cobalt Mines, Ltd. (1933-1935)
  • Consolidated Coppermines Co. (1922-1939)
  • Bidgood-Kirkland Gold Mines; Gordon Lebel Mines Ltd. (1945-1949)
  • Quebec Platinum Mines Limited; Quebec Cobalt & Exploration Ltd. (1955-1965)
  • Mesabi Iron Company [with brother Arnold Hoffman] (1939, 1959)

Blueprint of Smith Cobalt geology

Box 3 -- Operational documents, maps, diagrams, photographs and correspondence from mining operations in which Hoffman was involved, some with his brother Arnold Hoffman (1922-1964). Includes:

  • Easterly Mine, Waldo district, Oregon, Gold Operators, Inc. (1911, 1933-1936)
  • Notes on site visits, Gold Operators, Inc. (1934-1935)
  • Gold Operators (Canada) Ltd. (1937-1956)
  • Field notebooks on American Metals Co. claims, Duprat Township, Quebec Canada (1927); Walker Lease, Cripple Creek, Colorado (1930)
  • Calcite Operators Inc. (1942-1944)
  • Field notebooks by Hoffman and others through Canada and the US West (1922-1964)