Joe Stein Air and Radiation Division Region 8 U.S. Environmental Protection Agency 1595 Wynkoop St. Denver, CO 80202 Electronic Filing Regulations.gov Re: Comments on Proposed Air Plan Approval; South Dakota; Regional Haze Plan for the Second Implementation Period [EPA Docket No. EPA–R08–OAR–2024–0609] Dear Mr. Stein, The National Parks Conservation Association (NPCA), Sierra Club and