Colo. Rev. Stat. § 24-32-108
The division of local government, with the cooperation of the secretary of state, shall promptly establish and maintain on a current basis, as a public record, a file listing by name all incorporated towns, cities, or cities and counties of the state, referred to in this part 1 as "municipalities", with the date of incorporation of each municipality, recording by legal description all changes in the boundaries of such municipalities, and accompanied by a map of the same. The division of local government shall maintain such a current and revised list for public inspection. Within thirty days after July 1, 1967, each municipality shall submit to the division of local government a description of its current legal boundaries, accompanied by a map, and the date of its municipal incorporation.
C.R.S. § 24-32-108