A person desiring to intervene shall serve a motion to intervene upon the parties as provided in § 15-6-5. The motion shall state the grounds therefor and shall be accompanied by a pleading setting forth the claim or defense for which intervention is sought. The same procedure shall be followed when a statute gives a right to intervene.
When the constitutionality of an act of the Legislature affecting the public interest is drawn in question in any action to which the state or an officer, agency, or employee of the state is not a party, the party asserting the unconstitutionality of the act shall notify the attorney general thereof within such time as to afford him the opportunity to intervene.
SDCL 15-6-24(c)