Colorado constitution
Article IV
Section 3

The officers named in section one of this article shall be chosen on the day of the general election, by the registered electors of the state. The governor and the lieutenant governor shall be chosen jointly by the casting by each voter of a single vote applicable to both offices. The returns of every election for said officers shall be sealed up and transmitted to the secretary of state, directed to the speaker of the house of representatives, who shall immediately, upon the organization of the house, and before proceeding to other business, open and publish the same in the presence of a majority of the members of both houses of the general assembly, who shall for that purpose assemble in the house of representatives. The joint candidates having the highest number of votes cast for governor and lieutenant governor, and the person having the highest number of votes for any other office, shall be declared duly elected, but if two or more have an equal and the highest number of votes for the same office or offices, one of them, or any two for whom joint votes were cast for governor and lieutenant governor respectively, shall be chosen thereto by the two houses, on joint ballot. Contested elections for the said offices shall be determined by the two houses, on joint ballot, in such manner as may be prescribed by law.