I do not have the time to participate in this one, but I have a profile that you can work on:
https://www.wikitree.com/wiki/Miller-37788
I live in rural northern California, in the redwoods. He has a grave here, that is not in any of the local graveyards. I found the grave when I was about 12 years old, and asked the local "old timers" about it. Only one knew anything, and he said that supposedly, the guy died of syphilis and they were afraid to bury him in the graveyard, for superstitious reasons.
The headstone is redwood, and is getting really hard to read. I will go by, and copy off the info, and post it on his profile sometime this week. My memory is "William D. Miller, born in Maine. Died (something, something) 1890, aged (something, something, something). I found some sources for him as an adult; he voted; he lived in logging areas, so he may have been a logger. Have not been able to connect him to any family.