That's not how trespass works. Marion county won't file even if there is signage if you weren't notified in person and it was documented.
Now, I'll tell a largely irrelevant "back in the day" story of when it could work like that. My maternal grandfather owned rural property that he only visited on weekends, as he lived and worked in the city. He had a good sized pond and had trouble with people fishing in it without permission. He posted no trespass signs without much affect. Finally he made "permission slips" (done on business cards) that said "________ has my permission to fish and or hunt on my property from X date to Y date" and his signature. He contacted the Sheriff, let him know of the arrangement, and gave him permission to issue trespass notices and arrest anyone without said card.
Now, that was about 30 years ago and in a very rural county with a small sheriff's department and one criminal court judge. Things are different now.
Yes, they are. Private property has little regard in the legal arena.