
U.S. EPA @EPA
#OTD in 1999, EPA issued the Regional Haze Rule to improve visual air quality in 156 national parks and wilderness areas across the country, including some of our most treasured natural areas, such as the Grand Canyon, Yosemite, Yellowstone, and the Everglades. #EPAat50 https://t.co/N6G4yFPhCU — PolitiTweet.org