Colo. Rev. Stat. § 29-8-111
Such notice shall be published in full one time in a newspaper of general circulation in the district or, if there is no such newspaper, by publication in a newspaper of general circulation in the county, city, or town in which said district is located. A copy of such notice shall be mailed to the last-known address of each owner of land within the proposed district whose property will be assessed for the cost of the improvement. The address to be used for said purpose shall be that last appearing on the real property records in the office of the county treasurer of the county wherein said property is located. In addition, a copy of such notice shall be addressed to "owner" and shall be so mailed, addressed to the street number of each piece of improved property to be affected by the assessment. Mailed notices and the published notice shall state where a copy of the resolution creating the district will be available for inspection by any interested parties.
C.R.S. § 29-8-111