Mo. Rev. Stat. § 72.130
Except as provided in sections 72.400 to 72.420, no city, town, village or other area shall be organized within this state under and by virtue of any law thereof, adjacent to or within two miles of the limits of any city of the first, second, third or fourth classification or any constitutional charter city, unless the city, town, village or other area be in a different county from the city or unless the city, town, or village is located within any county of the first classification with more than eighty-two thousand but less than eighty-two thousand one hundred inhabitants, except that a city, town, village or other area may be incorporated within the two-mile area if a petition signed by a number of voters equal to fifteen percent of the votes cast in the last gubernatorial election in the area proposed to be incorporated is presented to the existing city requesting that the boundaries of the existing city be extended to include the area proposed to be incorporated and if action taken thereon by the existing city is unfavorable to the petition, or if no action is taken by the existing city on the petition, then the city, town, village or other area may be incorporated after the expiration of one year from the date of the petition and upon a favorable majority vote on the question.
§ 72.130, RSMo
8/28/2003 (H.B. 166)