Idaho does not get the attention it deserves for dark skies. Most of the coverage goes to Utah, Arizona, and Colorado, but Idaho has something none of them can claim: it was the first state in the country to receive a designated International Dark Sky Reserve. That designation, covering nearly 1,500 square miles of the Sawtooth Range and surrounding wilderness, set a standard for reserve-level protection that other states have since followed.
Here are the best certified dark sky sites in Idaho.
Central Idaho Dark Sky Reserve — Bortle 2
Central Idaho Dark Sky Reserve was the first designated International Dark Sky Reserve in the United States. The reserve covers nearly 1,500 square miles of the Sawtooth National Recreation Area and surrounding wilderness in the central mountains of the state. The Stanley Basin sits at the center, a high mountain valley at 6,200 feet elevation surrounded by granite peaks with virtually no permanent artificial light within the reserve boundary. The Milky Way is visible on most clear nights from June through September. The combination of mountain scenery, genuine darkness, and the historical significance of the designation makes this the anchor of any Idaho stargazing trip.
Sawtooth National Recreation Area — Bortle 2
The Sawtooth NRA forms the core of the Central Idaho Dark Sky Reserve and protects more than 750,000 acres of mountain wilderness north of Sun Valley. The jagged granite peaks of the Sawtooth Range rise above a network of more than 300 alpine lakes and high meadows that see minimal light pollution year-round. The corridor around Stanley and Redfish Lake is the most accessible entry point, and the mountain backdrop makes it as visually compelling as any dark sky site in the West. Redfish Lake reflecting the Milky Way overhead is one of those images that does not need to be exaggerated.
Craters of the Moon National Monument — Bortle 2
Craters of the Moon preserves one of the most unusual landscapes in North America: a vast lava field covering more than 750,000 acres of the Snake River Plain. The monument is certified by DarkSky International, and the black lava surface has an advantage that most dark sky sites lack. It absorbs rather than reflects light, keeping ground-level scatter lower than the surrounding terrain would suggest. The result is a darker observing environment than the Bortle rating alone implies. On a moonless night the lava flows and cinder cones feel genuinely alien, which is exactly what the name promises.
City of Rocks National Reserve — Bortle 2
City of Rocks is a collection of massive granite spires in a remote valley of southern Idaho, historically a campsite along the California Trail where emigrants carved their names into the rock. Today it is a celebrated climbing destination that doubles as a certified dark sky site. The surrounding terrain is sparsely populated in every direction, and the rock formations create a dramatic foreground for nighttime photography. It is one of the more visually distinctive certified sites in the Pacific Northwest region.
Bruneau Dunes State Park — Bortle 2
Bruneau Dunes holds the tallest single-structured sand dune in North America, rising 470 feet above two small lakes in the high desert of southwestern Idaho. The state park is certified by DarkSky International and operates one of the few public observatories in the Idaho dark sky network, open to visitors on weekend evenings. The lakes below the dune reflect stars on calm nights, and the dune itself makes for an unusual foreground. Spring is the recommended season, before summer heat sets in and after winter storms clear.
Planning Your Trip
The Central Idaho mountains are snowbound from November through May at higher elevations, which compresses the prime stargazing season to June through October. July and August bring the clearest nights in the Stanley Basin, with low humidity and long stretches of stable weather. Temperatures drop fast after sunset at elevation. Even in July, nights in Stanley can dip into the 30s. Bring layers and check road conditions if you are heading into the backcountry.
The Sun Valley and Ketchum corridor to the south has more lodging options and makes a good base for exploring both the Sawtooth NRA and City of Rocks over a long weekend.