Colorado Constitution of 1876 Art. V, § 10. Each house to choose its officers

At the beginning of the first regular session after a general election, and at such other times as may be necessary, the senate shall elect one of its members president, and the house of representatives shall elect one of its members as speaker. The president and speaker shall serve as such until the election and installation of their respective successors. Each house shall choose its other officers and shall judge the election and qualification of its members.