Colorado was admitted to the Union on August 1, 1876, and elects senators to Senate Class II and Class III. Its current senators are Mark Udall and Michael Bennet. [edit] Class II | Senator | Party | Took office | Left office | Reason | Other offices/Notes | | Henry M. Teller |  | Republican | November 15, 1876 | April 17, 1882 | Resigned | Secretary of the Interior (1882–1885)
Also served in Colorado's Class III seat | | George M. Chilcott |  | Republican | April 17, 1882 | January 27, 1883 | Successor qualified | | | Horace Tabor |  | Republican | January 27, 1883 | March 4, 1883 | Retired | Lieutenant Governor of Colorado (1879–1883) | | Thomas M. Bowen |  | Republican | March 4, 1883 | March 4, 1889 | | Governor of the Idaho Territory (1871)
Justice of the Arkansas Supreme Court (1867–1871) | | Edward O. Wolcott |  | Republican | March 4, 1889 | March 4, 1901 | Lost re-election | | | Thomas M. Patterson |  | Democratic | March 4, 1901 | March 4, 1907 | Retired | | | Simon Guggenheim |  | Republican | March 4, 1907 | March 4, 1913 | | | John F. Shafroth |  | Democratic | March 4, 1913 | March 4, 1919 | Lost re-election | Governor of Colorado (1908–1912) | | Lawrence C. Phipps |  | Republican | March 4, 1919 | March 4, 1931 | Retired | | | Edward P. Costigan |  | Democratic | March 4, 1931 | January 3, 1937 | | | | Edwin C. Johnson |  | Democratic | January 3, 1937 | January 3, 1955 | Retired | Governor of Colorado (1933–1937; 1955–1957)
Lieutenant Governor of Colorado (1931–1933) | | Gordon L. Allott |  | Republican | January 3, 1955 | January 3, 1973 | Lost re-election | Lieutenant Governor of Colorado (1951–1955) | | Floyd K. Haskell |  | Democratic | January 3, 1973 | January 3, 1979 | Lost re-election | | | William L. Armstrong |  | Republican | January 3, 1979 | January 3, 1991 | Retired | Colorado Senate Majority Leader (1969–1972) | | Hank Brown |  | Republican | January 3, 1991 | January 3, 1997 | Retired | | | Wayne Allard |  | Republican | January 3, 1997 | January 3, 2009 | Retired | | | Mark Udall |  | Democratic | January 3, 2009 | Present | Incumbent | | [edit] Class III | Senator | Party | Took office | Left office | Reason | Other offices/Notes | | Jerome B. Chaffee |  | Republican | November 15, 1876 | March 4, 1879 | Retired | Speaker of the Colorado Territorial House of Representatives (1863) | | Nathaniel P. Hill |  | Republican | March 4, 1879 | March 4, 1885 | | | | Henry M. Teller | | Republican | March 4, 1885 | March 4, 1909 | Retired | Secretary of the Interior (1882–1885)
Also served in Colorado's Class II seat | | Silver Republican | | Democratic | | Charles J. Hughes, Jr. |  | Democratic | March 4, 1909 | January 11, 1911 | Died | | | Charles S. Thomas |  | Democratic | January 15, 1913 | March 4, 1921 | Lost re-election | Governor of Colorado (1899–1901) | | Samuel D. Nicholson |  | Republican | March 4, 1921 | March 24, 1923 | Died | | Alva B. Adams |  | Democratic | May 17, 1923 | November 30, 1924 | Retired | | | Rice W. Means |  | Republican | December 1, 1924 | March 4, 1927 | | | | Charles W. Waterman |  | Republican | March 4, 1927 | August 27, 1932 | Died | | Walter Walker |  | Democratic | September 26, 1932 | December 1, 1932 | Lost special election | | | Karl C. Schuyler |  | Republican | December 7, 1932 | March 4, 1933 | Lost election to full term | | | Alva B. Adams | | Democratic | March 4, 1933 | December 1, 1941 | Died | | | Eugene Millikin |  | Republican | December 20, 1941 | January 3, 1957 | Retired | | | John A. Carroll |  | Democratic | January 3, 1957 | January 3, 1963 | Lost re-election | | | Peter H. Dominick |  | Republican | January 3, 1963 | January 3, 1975 | Lost re-election | Ambassador to Switzerland (1975) | | Gary Hart |  | Democratic | January 3, 1975 | January 3, 1987 | Retired | | | Tim Wirth |  | Democratic | January 3, 1987 | January 3, 1993 | Retired | | | Ben Nighthorse Campbell |  | Democratic | January 3, 1993 | January 3, 2005 | Retired | Olympic judo athlete (1964) | | Republican | | Ken Salazar |  | Democratic | January 3, 2005 | January 20, 2009 | Resigned | Secretary of the Interior (2009— )
Colorado Attorney General (1999–2005) | | Michael Bennet |  | Democratic | January 21, 2009 | Present | Incumbent | | [edit] See also [edit] References |
