SDCL § 15-6-24(a): Intervention of right.

Upon timely application anyone shall be permitted to intervene in an action:

(1) When a statute of the state confers an unconditional right to intervene; or

(2) When the applicant claims an interest relating to the property or transaction which is the subject of the action and he is so situated that the disposition of the action may as a practical matter impair or impede his ability to protect that interest, unless the applicant's interest is adequately represented by existing parties.