Colo. Rev. Stat. § 30-28-114
The board of county commissioners may provide for the enforcement of the zoning regulations by means of the withholding of building permits, and, for such purpose, may establish and fill a position of county building inspector and may fix the compensation attached to said position, or may authorize one or more administrative officials of the county to assume some or all functions of such position in addition to their customary functions. Such board may also fix a reasonable schedule of fees for the issuance of such permits. After the establishment of such position and the filling of the same, it shall be unlawful to erect, construct, reconstruct, alter, or change the use of any building or other structure within the unincorporated territory covered by such zoning regulations without obtaining a building permit from such county building inspector. Such building inspector shall not issue any permit unless the plans for the proposed erection, construction, reconstruction, alteration, or use fully conform to all zoning regulations then in effect.
C.R.S. § 30-28-114