Grand Canyon National Park has been certified as an International Dark Sky Park/Harun Mehmedinovic, SKYGLOW Project

Proof of both the National Park Service's determination to reduce light pollution and the wonders of the night sky to behold over parks comes with the addition of Grand Canyon National Park to the growing list of park units certified as International Dark Sky Parks by the International Dark Sky Association.

It didn't seem too terribly long ago that you could count the number of certified parks on one hand. Grand Canyon becomes the 27th unit to gain the certification.

To celebrate this milestone, Grand Canyon staff will hold a ceremony on the South Rim at Mather Amphitheater at 10 a.m. on this Saturday. Park leadership, Grand Canyon Conservancy management, a historian from Lowell Observatory, and a representative from the International Dark Sky Association will speak about the importance of this certification. The park will be given a framed certificate as a symbolic gesture from the International Dark Sky Association for achieving this certification. The ceremony kicks off the first day of the 29th annual Grand Canyon Star Party, an eight night event from June 22-29 celebrating the park's dark sky heritage.

In 2016, after an initial inventory and assessment of more than 5,000 exterior light fixtures, Grand Canyon National Park was given Provisional International Dark Sky Park status. The provisional status gave the park three years to retrofit 67 percent of the light fixtures to be dark-sky compliant in order to achieve full certification. At the time, 35 percent of the lights were already dark-sky compliant.

In late May of 2019, the park completed the retrofit process of an additional 34 percent of the light fixtures, bringing the total dark-sky compliant lights in the park up to 69 percent. The process was reviewed and accepted by the International Dark Sky Association, officially certifying Grand Canyon National Park as the newest International Dark Sky Park in the National Park Service. The park plans on making 90 percent of the lights dark-sky compliant by 2024. 

The funding for this ambitious project came almost entirely from Grand Canyon Conservancy, the official non-profit partner of the park. GCC relies on donations in order to achieve long-term renovations and educational programming for the park. GCC's current projects include preserving dark skies, renovating the park's trails, creating a trail endowment, reimagining the Desert View Watchtower complex to focus on giving voice to Grand Canyon's indigenous tribes, and much more. GCC raised nearly six figures towards the International Dark Sky Park status initiative.

The three-year retrofit process was divided into three phases. Park management started phase one with retrofitting the South Rim Lodge area which is part of the Historic Village District and involved coordination with the State Historic Preservation Office. About half of the 198 lighting fixtures themselves were historic and could not be dismantled. For those fixtures, the park simply exchanged bulbs within the historic fixtures. Bulbs with a color correlated temperature (CCT) of 2400K were used for many of these fixtures.

Non-historic fixtures were retrofitted with one of a few varieties of fully-shielded fixtures or simply removed. Fixtures were chosen to aesthetically compliment the era of the building to which it was affixed. Park management also coordinated with Xanterra, one of the park's concessioners, to retrofit the light fixtures on the buildings managed by Xanterra. Xanterra hired contractors to install the retrofits; the new fixtures and bulbs were purchased by GCC.

The second and third phase of the process focused on the retrofitting of residential neighborhoods within the park as well as the Maswik Lodge, Grand Canyon School, the Recreation Center and the rest of the buildings in Historic Village District.

Grand Canyon National Park is home to a large community and it is the only national park with a K-12 school. Over 1,500 fixtures were retrofitted in these areas to be dark-sky compliant. The next phases of the process will focus on the North Rim, Desert View, Phantom Ranch, and Tuweep to achieve 90 percent compliance.