Rock Springs, WY's night sky, measured from orbit
Satellite radiance puts Rock Springs in the suburban band. Light dome dominates much of the sky. Only the brightest stars and planets stand out clearly. Only 46.8% of the 3,206 cities measured here read darker than Rock Springs.
Note the source: a satellite reading of upward light, not a visual Bortle scale reading. The two measure related but different things.
How far Rock Springs is from a meaningfully darker sky
The closest place in this dataset with a meaningfully darker sky is Green River, WY, roughly 14 miles away in a straight line, rated suburban edge. Road distance will be more.
Green River, WY is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
How Rock Springs compares nationally
About 22,967 people live in Rock Springs, WY, sized enough to appear in this dataset of 3,206 incorporated US cities. Rock Springs places 1,493 of 3,206 cities in this dataset's darkest-to-brightest order.