EPA is taking final action to approve a revision to the South Dakota State Implementation Plan (SIP) addressing regional haze submitted by the State of South Dakota on January 21, 2011, along with an amendment submitted on September 19, 2011. EPA has determined that the plan submitted by South Dakota satisfies the requirements of the Clean Air Act (CAA or Act) and our rules that require states to prevent any future and remedy any existing man-made impairment of visibility in mandatory Class I areas caused by emissions of air pollutants from numerous sources located over a wide geographic area (also referred to as the "Regional Haze program").