1897
February 7, Berkeley, California
March 1, San Francisco
March 17, Berkeley, California
April 12, London
November 21, Coolgardie, Western Australia
1898
April 2, Coolgardie, Western Australia
1899
July 9, Tientsin (Tianjin), China
1900
January 20, Tientsin (Tianjin), China
February 15, Tientsin (Tianjin), China
1902
February 20, Chicago
October 28, London
1904
May 31, London
1905
May 17, Monterey, California
May 26, San Francisco
1906
June 26, London
July 31, London
September 22, London
1910
April 29, London
1911
May 22, London
May 24, London
1917
February 2, New York
February 10, New York
February 14, New York
F.A. Govett to Herbert Hoover 1906
Lou Henry Hoover to R.A.F. Penrose, concerning Herbert Hoover's book, Principles of Mining, circa 1909
R.A.F. Penrose to Herbert Hoover 1915
Ellen Coit Elliott to R.A.F. Penrose, concerning Belgian relief fundraising activities at Stanford University 1916
R.A.F. Penrose to Alonzo Taylor 1916
Correspondence between R.A.F. Penrose and his brother, Senator Boies Penrose, regarding Hoover's activities 1917
Bradley Stoughton to R.A.F. Penrose, regarding election of Herbert Hoover honorary as honorary member of the American Institute of Mining Engineers 1917
Correspondence to R.A.F. Penrose from the Hoover Business League 1928
George Wharton Pepper to R.A.F. Penrose, undated