On my return flight from BC this weekend, a thick hazy layer was just below me. I’m at 12,500 feet, which is about 500 feet above this peak, one of the highest on my flight path. They were quite interesting. (I was never in danger. It was a smooth flight, I was just above the hazy layer and could always see what was ahead of me, and the ghostly ground below.
Once past the mountains and over Alberta, the evening sunlight made farms look very green.