This joint resolution nullifies the Environmental Protection Agency (EPA) final rule titled Air Plan Approval; South Dakota; Regional Haze Plan for the Second Implementation Period (90 Fed. Reg. 41893) and published on August 28, 2025. The final rule approved South Dakota’s revision to its state implementation plan to satisfy the requirements of the EPA’s regional haze rule. (The regional haze rule requires states to take actions to improve visibility in national parks and wilderness areas.)