C.R.S. § 31-2-106

(1) Any city or town which is formed, organized, or incorporated and which exercises the rights and powers of a city or town and has in office a governing body exercising its duties is deemed legally incorporated. The legality of such formation or organization shall not be legally denied or questioned after six months from the date thereof; it is deemed a legally incorporated city or town; and its formation, organization, or incorporation shall not thereafter be questioned. (2) All cities and towns organized pursuant to the general laws of this state prior to July 1, 1975, are hereby validated, and the proceedings adopted therein, and obligations incurred by such cities and towns are hereby validated and confirmed. (3) All streets, parks, and other places designated or described as for public use on the map or plat of any city or town are public property, and the fee title thereto is vested in such city or town.