“””Note to Self: Stay away from Denver.”””””””””
In the late 1970’s I drove from North Dakota to California for a little vacation. As I got closer to Denver I couldn’t figure out what that dark cloud over the city was. It was heavy smog. I had never seen smog before and couldn’t believe how dirty the place was.
Maybe the smog is what caused people there to become so nuts.
Or the over indulgence of other "smoke".
We often get atmospheric inversions where the air at higher altitudes is warmer than the air at lower. It creates a clearly defined line holding all exhaust etc below. With unleaded gas and scrubbers, etc, we rarely have bad brown days like we used to, even with the explosion in population but still get the inversions (mostly in the winter).