http://www.hcn.org These are the search results for the query, showing results 1 to 1. http://www.hcn.org/issues/44.12/congress-thwarts-effort-to-reduce-grand-canyon-noise-pollution A last-minute provision in July’s transportation bill overrules Park Service recommendations for quieting the cacophony of sightseeing air traffic over the Grand Canyon. No publisher Emily Guerin Grand Canyon air tours Grand Canyon Backpackers Air-tour industry National Park Service John McCain Transportation bill National park noise pollution Wilderness experience noise pollution 2012-07-17T22:34:41Z News Article