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photo courtesy National Park Service Haze fills the Grand Canyon in this photo from 1994. Courtesy | Colorado State University These photos show a hazy day and a clear day in Bryce Canyon National Park. The photos, ta Al Hartmann | The Salt Lake Tribune The Environmental Protection Agency estimates that installing selective catalytic reduction Al Hartmann | The Salt Lake Tribune PacifiCorp's Huntington coal-fired power plant could be producing more power -- and emitting