re: M31....a spot: Nice!
It's really an excellent picture! So too, your others.
When I'm in a really dark sky location, typically in New Mexico, though I have performed the exercise in Wyoming and Colorado as well, I like to tease the Andromeda Galaxy out of the surroundings without a telescope. I've seen both M31 and M33 this way, though the M33 sighting was admittedly somewhat dubious -- the slightest of smudges in its location only visible with averted vision. I have only glimpsed M31 once with the naked eye while in my home state of California -- our skies are perpetually way too murky.
Cheers, BRFelix