The Environmental Protection Agency (EPA) is finalizing approval of a State Implementation Plan (SIP) revision submitted by the State of South Dakota through the South Dakota Department of Environment and Natural Resources (DENR) on January 27, 2016. South Dakota's January 27, 2016 SIP revision (Progress Report) addresses requirements of the Clean Air Act (CAA or Act) and the EPA's rules that require each state to submit periodic reports describing progress towards reasonable progress goals (RPGs) established for regional haze and a determination of the adequacy of the state's existing SIP addressing regional haze (regional haze plan). The EPA is finalizing approval of South Dakota's determination that the State's regional haze plan is adequate to meet these RPGs for the first implementation period covering through 2018 and requires no substantive revision at this time.