Colo. Rev. Stat. § 31-23-104
Any such plat shall be acknowledged in the manner of a deed by the owners and proprietors of the lands designated upon any such plat before some officer authorized to take the acknowledgment of deeds. A copy thereof so acknowledged shall be filed in the office of the county clerk and recorder of the county where such lands are situated and also in the office of the clerk of any such city or town. When any such plat embraces in its description any street, highway, park, square, or other lands owned or held by the city or town for any public use or otherwise, said plat shall be acknowledged in behalf of the city or town by the mayor of the city or town when authorized by the resolution or ordinance of the governing body. Any such acknowledgment of any owner or proprietor may be made for such owner or proprietor by any attorney-in-fact duly authorized by deed.
C.R.S. § 31-23-104
This section is similar to former § 31-1-403 as it existed prior to 1975.