BORTLE CLASS 1 / SKY KEY
Excellent dark-sky site
The dark end of the scale. The Milky Way shows extensive structure and the sky itself becomes part of the landscape.
1
HOW TO READ IT
One number is a sketch of the sky, not the whole night.
A Bortle class describes what the sky looks like under particular conditions. Walk across a large park, turn toward a town, add snow or smoke, and the view can change. Use the number to compare darkness quickly, then read the stop page for the horizon, headlights, access and everything else that decides whether the place actually works.
Colorado stops currently logged as Bortle 1
Colorado Trail / Willow Creek Dark-Sky PointSource-supported Bortle 1 at 37.93819, -107.07829. The supplied Light Pollution Map sky-brightness readout shows SQM 22.00 mag/arcsec², zero modeled artificial brightness and about 3,745 m elevation. Treat the class as a sky-model reference until moonless field checked. ↗Kim / Southeast Colorado dark countryEstimated Bortle 1 for the darker open country south of Kim, away from the town itself. This is a modeled/source-supported estimate rather than a field measurement; the eastern horizon can brighten toward Springfield. ↗