Summer is a time when American families plan vacations. Many are centered on the natural beauty of our country and the National Parks System. However, what many tourists may not anticipate is that the destination of their journey is being impacted by air pollution in the form of soot and haze, despite laws that were put into place as far back as the 1970s.

via Marcia G. Yerman: In America’s National Parks, Air Pollution Knows No Boundaries.