In April, a set of voluntary guidelines for air tours in Denali National Park was released, meant to minimize noise intrusions on backcountry hikers.  An Aircraft Overflights Advisory Council spent a bit over a year coming up with the proposals, which included asking pilots heading for the summit of Mt. McKinley/Denali to avoid two high-altitude camps used by people climbing the mountain.

A “sound station” on the Ruth Glacier is monitoring the noise level of aircraft landing on the glacier. NPS Photo.

Likewise, Kahiltna Glacier campers have been subject to planes climbing to cross Kahiltna Pass, where pilots are encouraged to climb to altitude before approaching the pass.  According to the Denali website, these “best practices” are designed to safely reduce sound impacts in key areas, and are subject to refinement and revision as operational experience is gained.  The Park Service is monitoring the effectiveness of the measures; Charlie Sassara, who is a member of the Council, says that “we will now try to look at additional mitigation measures to enact in 2010.”