How dark is the sky in Oregon?
Sky darkness for 58 towns and parks in Oregon, worked out from NASA satellite images of light at night (2025). 48 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Fremont National Forest (21.90, Bortle 2), the brightest Portland (17.62, Bortle 8).
19
Bortle class, 1 pristine to 9 city center
park or dark-sky place
city
Numbers like 21.95 or 16.97 are the brightness of the sky overhead on a clear, moonless night, in mag/arcsec². The scale runs backwards: a lower number means a brighter sky, from about 22 for a natural sky to about 17 in a city center.
How the readings are made
Darkest skies in Oregon
- Fremont National ForestBortle 221.90
- John Day Fossil Beds National MonumentBortle 221.90
- Fremont-Winema National ForestBortle 321.89
- Hells Canyon National Recreation AreaBortle 321.88
- Malheur National ForestBortle 321.88
Among the places on this site. Plenty of land between them is just as dark, with no town or park to name it by.
Brightest city skies in Oregon
All 58 places in Oregon
Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Albany6Arcadia Beach State Recreation Site4Beaverton8Bend7Benson State Recreation Area4Bob Straub State Park4Boiler Bay State Scenic Viewpoint4Bradley State Scenic Viewpoint4Cape Arago State Park4Cape Lookout State Park4Cascade-Siskiyou National Monument4Corvallis6Crater Lake National Park3Darlingtonia State Natural Site4Deschutes National Forest4Devils Punch Bowl State Natural Area4Ecola State Park4Emigrant Springs State Heritage Area4Eugene8Face Rock State Scenic Viewpoint4Fort Rock Cave3Fremont National Forest2Fremont-Winema National Forest3Gresham7Hells Canyon National Recreation Area3Hillsboro7Humbug Mountain State Park3Jessie M. Honeyman Memorial State Park4John B. Yeon State Scenic Corridor4John Day Fossil Beds National Monument2Malheur National Forest3Medford8Mount Hood National Forest4Mount Hood National Recreation Area4Newberry National Volcanic Monument3Ochoco National Forest3Oregon Dunes National Recreation Area4Oregon National Forest4Oswald West State Park4Peter Skene Ogden State Scenic Viewpoint4Port Orford Heads State Park4Portland8Prospect State Scenic Viewpoint4Rogue River-Siskiyou National Forest3Salem8Sarah Helmick State Recreation Site4Shore Acres State Park4Silver Falls State Park4Siuslaw National Forest4Smith Rock State Park4Sunset Bay State Park4The Cove Palisades State Park4Umatilla National Forest3Umpqua National Forest3Wallowa-Whitman National Forest3White River Falls State Park3Willamette National Forest4William M. Tugman State Park4