This is sunset over the Sheephole Mountains, very near to the spot in the desert where I do my astrophotography. It's a Bortle 2 area, which means it's very nearly the darkest possible area for stargazing. That compares to Bortle 8-9 in my backyard.
Bortle 1 is the darkest sky possible. Death Valley is Bortle 1. Some of Northern California around Lassen and Shasta is Bortle 1. Most of Nevada away from I15 and I80 is Bortle 1.

What is the reading for Parkfield.
Bortle 1 is a far away fantasy for my region.
Also isn't clear to me how you measure a Bortle.
Check this out: https://en.wikipedia.org/wiki/Bortle_scale