Challis
Challis is the largest city in Custer County, Idaho, United States. Challis was founded in 1878 and named for A.P. Challis, who was a surveyor when the townsite was laid out. The remoteness of the town, its dry air, plus its elevation of 5,200 feet (1,600 m) all contribute to the darkness of its night sky, about class 3 in the Bortle scale and reaching class 2 only a few miles (km) away. The fellow stargazer who recommended this place to EarthSky said it has: “the best visibility I’ve ever seen, and I am 68. Amazing clarity! I have been in many remote areas, but I’ve never seen anything like it!”