N.M. Stat. § 3-16-2
When the total population of any combined municipal organization shall be at least fifty thousand inhabitants, a city-county government may be organized as hereinafter provided. The legislative authority of any city within a combined municipal organization by ordinance, and the county commissioners of a county within the same combined municipal organization, by resolution, may express their desire that the question of the formation of a combined city and county municipal corporation shall be submitted to the voters of the city and the county outside the city, in accordance with Article 10, Section 4 of the constitution of New Mexico, at a special election called and held as hereinafter provided. In the event approval is obtained by ordinance in the city and by resolution of the county commissioners, then the governing body of any city may appoint seven members who are residents of the city, and the county commissioners may appoint seven members who are residents of the county, making a total of fourteen members, which will form a city and county charter committee. Said charter committee shall meet to draft a charter not inconsistent with the constitution and laws of New Mexico pertaining to city charters. The proposed charter must be approved by a majority of the fourteen appointed members of the charter committee. In the event said proposed charter is approved by the committee, it shall be submitted separately to the county commissioners and governing body of the city, and must be approved by a majority vote of each of these bodies. In the event said bodies approve the proposed charter, then, within sixty days, the county commissioners shall call a special election to be held in the combined municipal organization for the purpose of voting upon the question of city-county consolidation and upon the proposed charter therefor. The special election shall be called, conducted and canvassed in the same manner as general elections for the election of county officers are called, conducted and canvassed; provided, that the vote of electors in voting divisions in each election unit upon each proposition shall be separately counted, canvassed and kept. The ballot for such special election shall be substantially as follows:
"City and County Consolidation: Shall the city of ______ (here insert name of city) be consolidated with the remainder of the county of ______ (here insert name of county in which the city is located) as a political subdivision and become a combined city and county government? YES ___ NO ___
Shall the City and County of ______ (here insert name of city and county) adopt the proposed city and county charter? YES ___ NO ___."
A copy of the proposed charter shall be posted at or near the front entrance of each voting division in plain view of the electors desiring to vote thereon. Each registered voter of the city and county shall be entitled to vote in the precinct or election district in which he is registered, and the propositions shall be submitted in such manner that the voters may vote for or against them. If a majority of the voters voting on the propositions in the city and a majority of the voters voting on the propositions in the county outside the city vote in favor of the propositions submitted, a city and county government for the combined municipal organization shall be established in accordance with Sections 3-16-1 through 3-16-18 NMSA 1978. If a majority vote of either election unit is against the proposition of consolidation, the proposition shall not again be submitted to the voters of the combined municipal organization within two years of the date of such election. The cost of the election and preparing the proposed city and county charter shall be apportioned between, and paid by, the city and county in proportion to the number of votes cast on the proposition inside the city and the number of votes cast in the county outside the city.
NMS § 3-16-2