Whenever twenty percent of the qualified electors, as determined by the vote cast in the last preceding gubernatorial election, residing in any rural territory, equivalent in area to one township or more not presently served by an existing emergency medical service, elect to form, organize, establish, equip, and maintain a rural ambulance service district, they shall signify their intention by presenting to the county auditor of the county or counties in which the territory is situated a petition setting forth the desires and purposes of the petitioners.