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plawrence
Mostly good information in the article, expect for one blurb: "But, notes guidebook author and photographer James Kaiser, Yosemite is located in a remote, high altitude area free of light and air pollution..."
Ah, no. Sadly, Yosemite does suffer, at times significantly, from air pollution, and even to some degree, even light pollution, though not as much as in more urban areas.
The National Park Service does have a philosophy of reduced light pollution. If you try walking any lit parking lot in Yosemite NP at night, there are few lights and the ones that are there are intentionally set for low output. It gets to the point where it helps to carry a flashlight even to just get from your car to your room.
I don't know if Yosemite goes as far as some places. Bryce Canyon NP is well known for its nighttime guided walks, where one is encouraged to just let the eyes adjust to the lack of light. I recall some NPS nighttime programs recommend the use of red lights (I once bought a lens kit with a red filter for my Petzl headlamp) to get around. I don't know what the red light is supposed to do, but I'm guessing it has something to do with light pollution.