Does this tool take into account elevation? The Mt. Wilson observatory, for instance, being on the outskirts of LA, is in a red zone on that map, yet is still a great place to stargaze.

Not that this map isn't useful and insightful, but perhaps it can make things seem worse than they really are? As long as you have mountains around you, it's not like you can't go there to see the stars with the naked eye. Last year, that comet was pretty easy to see from up there.