Special election to fill vacancy caused by the death of Samuel Nicholson on March 24, 1923. Alva B. Adams was appointed to the seat on May 17, 1923, pending the special election. Adams did not run in the special election, opting instead to run in the concurrent regular election for Colorado's other Senate seat.
Source for Popular Vote data: Colorado Secretary of State. Abstract of Votes Cast at a General Election Held on Tuesday, November 4, A.D. 1924, Colorado Secretary of State (https://www.sos.state.co.us/pubs/elections/Results/Abstract/pdf/1900-1999/1924AbstractBook.pdf) (accessed 21 Sep 2023)