In a contest as to a submitted or referred question voted upon in more than one county, the summons and complaint must be served on the attorney general. In other cases involving a submitted or referred question, the court shall, upon filing the complaint, direct by order the service upon such persons or officials as the court believes might be interested in resisting the relief sought. Any person on whom such complaint is served may answer the complaint, and shall thereafter be deemed a party. After commencement of a contest involving a submitted or referred question, any voter who was entitled to vote on such question may be permitted to intervene as a party plaintiff or defendant.
SDCL 12-22-15