Seek out who pays taxes on the properties.
Township assessor might be a good start.
I'm not in Texas ,but here I have acquired information to locate the taxpayers to ask permissions that way.
One was a caretaker that for some reason was keeping track of the estate. Family still existed and surprised me with a visit at an abandon homestead. Good thing I had permission...
Most township officials have been as polite to me as I have them.
Some understandably are guarded about others contact information.
Updated/current plot books .often at a nearby library
audacity find my iphone origin have turned up owners names..
One name I looked up on the internet (a parcel of vacant forest adjacent to me I was curious about it's future as no one has been seen there a decade).
Found the owner recently deceased. His family info had I wanted to locate them ,but left the issue be..
You can find out who owns a site.
Do it legal. Lot's more enjoyable that what could happen.