Mo. Rev. Stat. § 321.210
On the first Tuesday in April after the expiration of at least two full calendar years from the date of the election of the first board of directors, and on the first Tuesday in April every two years thereafter, an election for members of the board of directors shall be held in the district. Nominations shall be filed at the headquarters of the fire protection district in which a majority of the district is located by paying a filing fee equal to the amount of a candidate for county office as set forth under section 115.357 and filing a statement under oath that the candidate possesses the required qualifications. The candidate receiving the most votes shall be elected. Any new member of the board shall qualify in the same manner as the members of the first board qualify.
§ 321.210, RSMo