BORTLE CLASS 3 / SKY KEY
Rural sky
A dark rural observing sky with some distant glow but plenty of contrast left for deep-sky observing.
3
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 3
Black Canyon of the Gunnison National ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Browns Canyon National MonumentEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗C Lazy U RanchEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗CampVEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Crawford State ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗CrestoneEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Cuchara / Bear & Blue LakesEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Curecanti National Recreation AreaEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Eleven Mile State ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Elkhead Reservoir State ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Florissant Fossil Beds National MonumentEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Grand Mesa ObservatoryEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Gunnison Valley ObservatoryEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Hovenweep National MonumentEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗John Martin Reservoir State ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Loveland PassEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗NorwoodEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Nucla & NaturitaEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Paonia State ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗PaoniaEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Pawnee National GrasslandEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Ridgway State ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗RidgwayEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Rocky Mountain National ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Smokey Jack ObservatoryEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Southern Colorado Astronomical ParkEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Top of the PinesEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗Westcliffe & Silver CliffEstimated Bortle 3 from modeled sky-brightness/light-pollution data at the guide location. Bortle is observational, so treat this as roughly ±1 class until field checked. ↗