What “International Dark Sky Park” means

Who certifies

International Dark Sky Places are certified by DarkSky International, a nonprofit formerly known as the International Dark-Sky Association. The program grew out of Flagstaff, Arizona, which was recognized in 2001 for its outdoor lighting policy. The first International Dark Sky Park followed in 2007: Natural Bridges National Monument in Utah.

The organization now counts more than 200 certified places in 22 countries on six continents. Certification is not a government designation, although many certified sites are national and state parks whose managers applied for it.

Five categories

• ParksPublicly or privately owned conservation areas that use good outdoor lighting and offer dark sky programs to visitors. Most of the places in our list are Parks.
• SanctuariesThe most remote, and often darkest, places in the world, whose conservation state is most fragile. Katahdin Woods and Waters in Maine is one.
• ReservesA dark core zone surrounded by a populated periphery, where policy controls protect the darkness of the core.
• Urban Night Sky PlacesSites in or near cities that offer an authentic nighttime experience despite significant artificial light around them.
• CommunitiesCities and towns with quality outdoor lighting rules that teach residents why dark skies matter.

What a park has to do

A dark sky overhead is not enough; the site has to manage its own light and teach visitors about the night. The certified parks show what that means in practice:

• Fix the fixtures. Grand Canyon National Park was designated in 2016 and received full status in June 2019, after retrofitting more than 5,000 light fixtures.
• Or have none. Obed Wild and Scenic River has no permanent outdoor lighting, and its managers have agreed not to install any.
• Run programs. Black Canyon of the Gunnison has held night-sky events with a local astronomy society since 1998; Mammoth Cave has offered night sky programs since 2017.

Gold and Bronze

Some certifications carry a tier that describes sky quality. Death Valley National Park holds the Gold Tier, the highest. Mammoth Cave National Park was certified at the Bronze Tier — still a protected, managed night sky, in a part of the country where more towns lie beyond the horizon.

What certification does not tell you

It does not promise clear weather, a moonless night or an open gate. Those are for you to check: the timing page covers the first two, and each park’s own website covers the third. The places themselves are in the list of parks.