The Darkest Skies
in Montana

"Smoke haze on the western horizon due to wildfires in Idaho, causing elevational extinction coefficients. Night was calm and clear. Computer issues only allowed one set of data to be taken for the night. SQM 21.6"

"High cirrus and poor tranparency, then clearing. M13, M31, and M33 all naked eye. Possible smoke induced inversion"

"Instrument set up on ridge just NW of the lookout. Seeing good, transparency very good. Glow to the northwest from airglow or aurora, not as bright east or southeast. Small light dome due north, fainter than Jupiter, another fainter smaller light dome northeast. Toward Columbia Falls lots of light, bright white glare illuminating the mountains from some sort of industrial yard, at least 10 unshielded lights visible, bright enough to kill night vision, casts shadows. Wonderful sky if you can get away from the glare. Milky Way directly overhead, very bright with much detail in Cygnus, all the rifts and holes apparent, North America nebula an easy visual object. Also in Cassiopeia much detail, bridge in the MIlky Way north of Mirfak visible. Sagittarius Milky Way washed out by Columbia falls area, the light dome of which extends 30 degrees from horizon upward, 40-50 degrees wide."

"Evening started out with widespread thunderstorms, which slowly dissipated through the night until skies were almost cloud free. The light dome of West Yellowstone (only 1.5 miles to the west) is very prominent and dominates the western horizon. Bozeman is barely visible to the north, likely due to low clouds in the distance. Even with the bright lights of West Yellowstone, you can see some good detail in the Milky Way before it becomes obscured by the light dome."

"Clear night with fair transparency above 20 degrees. Haze visible along the horizon. Seeing fair. Local light from the reservation was direct glare, while the light dome from Hardin was the largest. Billings and Sheridan light domes visible but not bright. Overall the direct glare was distracting, but blocking this allowed for dark adaptation. Milky Way was easily seen with detail in sagittarius, and dust lanes. Visible from tail of Scorpius in South to Cassiopeia. SQM 21.64 at 0130; SQM-L 21.63 at 0152."

"Some direct glare creating difficulties in dark adapting looking north. M13, 31, and 33 all visible naked eye. SQM measure of 21.77"

"Sky quality measurements were recorded at Skyline Vista in Theodore Roosevelt NP on 9/30/2010. The site demonstrated a scientific darkness reading of 21.45 SQM."

"Sky quality measurements were recorded at Oxbow Overlook in Theodore Roosevelt NP on 10/1/2010. The site demonstrated a scientific darkness reading of 21.45 SQM."

"Set up camera equipment on the trail to the camp. Clouds in the afternoon all cleared out by 9:00 pm, though it appeared as if some fire smoke moved through the northern horizon later in the night. Excellent night sky viewing from this park, rivaling sites on the Colorado Plateau. A single yard light on a ranch building 2.5 miles north was bothersome, otherwise no visible lights seen from this location. A very faint light dome from Butte (60 miles distant) and nothing apparent from Wisdom, the nearest community (9 miles). Very fine detail visble in the Milky Way, with the Prancing Horse easily seen and the dust lanes in great detail. Stars are visible to the horizon in the south. Saw limiting magnitude star of 7.2 in Draco. Mars and Jupiter very bright to the SE and SW."

"Clear skies, aside from some low clouds on the northern horizon, which mostly cleared out by 9:00 pm local time. Excellent site along the canyon rim with a direct view down into the town of Lovell. Another night of high airglow similar to the previous night at DETO. Milky Way overhead, but fine detail somewhat washed out toward the horizon and in the Sagitarrius star cloud by the airglow. Prancing Horse barely visible. Daytime visibilty slightly impaired by agricultural burning in the Big Horn Valley. The Devil Canyon Overlook is a great spot for observing the night sky or astrophotography. The Horseshoe Bend Campground is even more protected by terrain from the direct glare of Lovell."