SDCL § 1-26A-3: Time limit for challenging rule on procedural grounds.

Within one year of the effective date of a rule, an action or proceeding may be brought to contest the legality of any rule for the failure of the agency to comply with the procedural requirements of chapter 1-26. However, this section does not restrict a person's right to initiate an action or proceeding to challenge the legality of the substance of any rule.