Dark-sky places in the US

What dark-sky certification means

DarkSky International, a nonprofit formerly called the International Dark-Sky Association, runs the International Dark Sky Places program. It began in 2001, when Flagstaff, Arizona, became the first certified place for its lighting rules. To be certified, a place must use quality outdoor lighting, adopt policies that limit light pollution, keep up stewardship and educate the public. Certified places must keep up these practices to stay certified. The National Park Service, which manages many certified parks, treats a natural night sky as a resource to protect, just like wildlife or scenery.

The types of dark-sky places

• Dark Sky Parks are public or private protected areas with good lighting and night sky programs. Some park certifications carry a Gold, Silver or Bronze tier, with Gold the darkest.
• Dark Sky Sanctuaries are the most remote and often darkest places, where the night environment is most fragile.
• Dark Sky Reserves have a very dark core surrounded by a populated edge where lighting rules protect the core.
• Dark Sky Communities are cities and towns with strong outdoor lighting ordinances and public education. The sky in town is better than in most towns, not wilderness-dark.
• Urban Night Sky Places are parks and open spaces in or near cities that offer a real night experience despite surrounding light.
• DarkSky Approved Lodging is a separate certification for hotels, lodges and camps whose lighting protects a starry sky for guests.

DarkSky says parks, sanctuaries and reserve cores keep a sky full of stars, often with the Milky Way, visible on a typical clear night. To compare skies, our Bortle scale guide explains what each class of darkness lets you see.

How to plan a dark-sky trip around the Moon

Moonlight is the biggest natural source of skyglow. Near full Moon, only bright stars and planets stand out, even at the darkest park. The best window is the week or so around the new Moon. In the days after new Moon, a thin crescent sets in the evening, leaving the rest of the night dark; after full Moon, the Moon rises later each night, so the early evening is dark until it comes up. Each state page lists the moon-free nights for the coming months, and our Moon phase calendar shows every phase. Then check the weather, since clouds beat even the darkest sky, and plan to arrive before dark so you can find your spot and let your eyes adjust. Pairing a moonless night with a meteor shower peak makes a trip even better.