Dear 100 Hour Board,
Are there any abandoned places or ruins in Utah that one can legally go urban exploring in?
I find it funny how concerned about laws you are for being a pirate. Laws typically aren't very important to pirates, but I respect your dedication to following the law.
So, we aren't lawyers and we can't give you legal advice. I read several articles online and for most places in general, if there are no trespassing signs, or if you have to break something to enter a building, that's definitely trespassing. This appears to be the case even if the building is abandoned.
I wasn't able to find a list of places that are guaranteed to be legal for exploration, but I did find several lists of abandoned places. This list comes from the Daily Universe and these places are most likely legal to visit because this list was published on an official university source and BYU doesn't really encourage law breaking.
There's also a Utah Urban Exploration Facebook group. They might be a good source for finding experienced people with legal and safety tips.
I hope this helps! Remember to always be safe and careful while exploring.
P.S. There's also a cool place here at BYU that I'd rather keep on the DL. If you would like info please email me at firstname.lastname@example.org