C.R.S. § 39-5-103

In listing tracts or parcels of real property, the assessor shall identify the same by section, or part of a section, township, and range, and, if such part of a section is not a legal subdivision, then by some other description sufficient to identify the same. In listing town or city lots, he shall describe the same by number of lot and block, or otherwise, in accordance with the system of numbering or describing used by the town or city in which said lots are located.