Dark-sky places in Idaho

Stargazing in Idaho

Idaho’s dark skies cover a huge share of the state. The rugged wilderness of central Idaho is one of the largest remaining pools of natural darkness in the lower 48, and much of it has no electricity or cell service. Most of Idaho’s larger cities follow the Snake River in an arc across the south, leaving the interior dark. The Central Idaho Dark Sky Reserve, the first in the US, protects the Sawtooth country, with Ketchum and Sun Valley on its edge. In the south, Craters of the Moon on the Snake River Plain, City of Rocks near the Utah line and Bruneau Dunes on the edge of the Owyhee desert all hold Dark Sky Park status.

Sun Valley Resort

Sun Valley Resort is a year-round mountain resort in Sun Valley, best known for skiing, on the edge of the Central Idaho Dark Sky Reserve. It holds DarkSky Approved Lodging certification for its outdoor lighting. The resort says it is adding guided stargazing programs, astronomy events and night-sky education for guests, and it points visitors to dark viewing spots nearby, from the top of Bald Mountain to the meadows of Trail Creek and nearby Galena Summit. It is a convenient base for exploring the reserve, with skiing, hiking, biking and fly fishing by day.

Bruneau Dunes State Park

Bruneau Dunes State Park sits on the northern edge of the Owyhee desert, about halfway between Boise and Twin Falls, around the tallest single-structured sand dune in North America. It has three campgrounds, hiking trails, two fishable lakes and two public observatories, which open from April through October. The park replaced all of its outdoor lights with dark-sky-friendly fixtures, includes dark-sky messages in its programs and runs regular sky-quality surveys. It is open year-round for day use and camping, which makes it one of the easiest places in southern Idaho to combine a campsite with telescope viewing.

City of Rocks National Reserve

City of Rocks National Reserve, near the Utah line in Cassia County, protects tall rock spires and stretches of the California Trail. The Park Service and Idaho state parks manage it together, and its visitor center is at neighboring Castle Rocks State Park. Since certification, the reserve has added star parties, constellation tours, dark-sky junior ranger programs and telescope viewing through the year. It is open 24 hours a day year-round and offers camping, so you can stay among the rocks after dark. Winter weather can close some roads, so check conditions first.

Central Idaho

The Central Idaho Dark Sky Reserve covers 1,416 square miles of the Sawtooth Mountains, with parts of two wilderness areas at its core inside the Sawtooth National Forest. DarkSky International notes that the rugged terrain has kept power lines and development out, so much of the reserve has neither electricity nor cell service. Visitors reach the backcountry from 23 major trailheads for hiking, backpacking and horseback riding. Ketchum and Sun Valley sit on the reserve’s southern side. The Idaho Dark Sky Alliance works to protect the reserve and educate visitors.

Ketchum, Idaho

Ketchum is a mountain town of about 3,650 people in the Wood River Valley, next to Sun Valley, built on a mining boom and now known for skiing, arts and culture. It adopted its first comprehensive outdoor lighting ordinance in 1999 and updated it to meet DarkSky’s community standards, and it has committed to bringing city-owned lights into line. Ketchum also helped create the neighboring Central Idaho Dark Sky Reserve. For the darkest views, head out of town into the reserve.

Craters Of The Moon National Monument

Craters of the Moon protects a vast field of lava flows and cinder cones on the northern edge of the Snake River Plain, the largest young lava field in the lower 48 states. Settlers avoided this harsh ground, and the area is still sparsely populated, giving natural protection from new lights. The monument sits on the edge of central Idaho’s large pool of darkness and became an International Dark Sky Park in 2017; the Park Service calls it one of the best places in the country to stargaze. Check the park’s calendar and campground status before planning a night visit.