The Darkest Skies
in North Dakota

"Extensive lights and gas flares along horizon from NW to SSE. One installation at approximately 30° is very close and causes loss of night vision. Sky to the southwest not showing stars below 15° (might be clouds or haze). Almost entire perimeter of South Unit has some level of lights. Zenith is still relatively dark after sufficient adaptation. Shortly after sunset, thick haze layer from gas flares is very visible along north and ast horizon."

"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."

"SQM 21.03. High extinction. Main light from International Falls, scatteing on moisture in the air, increasing all sky pollution"

"Clouds but clearing. SQM 21.35. Light pollution residential and navigation bouy"

"Set up camera due north of the fort on the Rendezvous Grounds. An excellent evening with warm temperatures and almost no wind. The motin sensor light mounted amongst the HVAC equipment repeatedly turned on every few minutes even with no movement on my part and no obvious wildlife. The light, when on, is extremely bright and lights up the entire NW outer wall and a large area of the adjacent grounds. I tried covering it for the first set, but it was still too bright, but I got lucky in the second data set in that it was off when the camera was pointing in that direction. The only other outdoor light in the vicinity was in the upper parking lot, though it was fully shielded. It is too bright for the intended task (too many lumens). The light dome from Dickinson was easily visible to the ENE and Watford City somewhat visible to the SSE. A handful of yard lights can be seen around the horizon from private ranches, though they do not impact the night sky measures. The night sky quality was very good and details could be seen in the Milky Way. Perhaps the downturn in oil prices has reduced the activity in the surrounding area."

"Good visibility during the day. According to the weather record, it rained in the previous days. Duluth light dome is clearly visible. Zodiacal light is visible. Milky Way is visible overhead and to the north, and it spans about 50 degrees across the sky. M31 is moderately visible with naked eyes."