He was a fascinating guy, he really was.

https://www.legendsofamerica.com/we-sethbullock/

To this day, the Bullock Hotel in Deadwood has WONDERFUL food in their dining room, I've been there many times, but I refuse to stay overnight in the hotel - - it is said to be haunted by the spirit of Seth.  I'm not afraid of spirits but I don't want to be out there tempting them, either.  Nothng bad has ever happened there, that I know of, but there certainly have been sightings of spiritual creatures by reputable people.  It may not be Seth's spirit, at all, but there's definitely something there. 

If you're interested in following up on that aspect, you'll have to do your own research on it.  Gives me the willies!

***  You will notice I never refer to these things as ghosts.  Only use the word spirit unless you want to anger them, that's what I've been told.  A spirit will accept invitations to leave, whereas if referred to as a ghost, you just piss them off and they get testy and annoying.  How much of that is true, I do not know.  Your guess is as good as mine in that regard, but I'm not for being the "tester".