Denver Light Pollution

Light Pollution around Denver is a definitely an issue and in 2001 the Colorado Legislature passed a bill (HB 01-1160) to help reduce it. For example the 17 mile TREX project was specifically designed to reduce light pollution. There's a lot of controversery as to how effective it really is. Currently, from the map below you can see how bad it is, but time will tell.

The picture above was generated from the National Atlas of the United States (it's easy to generate one for your area). While it's a nice picture it has a few problems in that the data is old (e-470 doesn't show up on it yet) and there's been a lot of construction in the southeast around e470. There's another picture from Clear Dark Sky that has a better light sensitivity (the data from the National Atlas cuts-out at about 20 mags / sq arcsec or 4.5 on the Bortle scale), but it doesn't show roads or towns. Finally, I have a blow-up of the souteast centered around Elbert. Interestingly, the DAS site (just SE of where I-70 starts dipping SE) seems to be about a 3 on the Bortle scale.