N.M. Stat. § 3-21-3.1
In addition to the powers authorized in Sections3-21-2, 3-21-3 and 3-21-4 NMSA 1978, any county and any municipality may agree to authorize a joint municipal-county zoning authority to enact ordinances, regulations, or both, relating to approval and regulation of subdivisions within the extraterritorial zoning area as defined by the agreement creating the joint municipal-county zoning authority. Such subdivision ordinances and regulations shall be adopted, amended and enforced pursuant to Sections3-21-3 and 3-21-4 NMSA 1978, as appropriate. Such subdivision ordinances and regulations may define "subdivision" in a manner which differs from the definitions set forth in Subsection A of Section 3-20-1 NMSA 1978 and in Subsection I of Section 47-6-2 NMSA 1978. The joint municipal-county zoning authority may also modify portions of the comprehensive plan, provided that such modifications leave unchanged those portions in the comprehensive plan that are not in the extraterritorial area.
NMS § 3-21-3.1