On July 23, 2014, the United States Court of Appeals for the Eighth Circuit determined that a utility was entitled to intervene in a lawsuit brought by environmental protection groups against the U.S. Environmental Protection Agency (EPA) to require EPA to impose emission-control technology on Northern States Power Company’s (NSP) Sherburne County power plant (Sherco). National Parks Conservation Ass’n v. U.S. E.P.A., — F.3d —-, (8th Cir. July 23, 2014). EPA’s Regional Haze Rule, 40 CFR pt. 51, subpart P, establishes visibility protection requirements for many national parks and wildernesses, including Minnesota’s Voyageurs National Park and Michigan’s Isle Royale National Park. In 2009, the Department of the Interior (DOI) certified that visual impairments at the two parks were reasonably attributable to pollution emissions from…