It is against the law in Texas to cross on to someone else's property with a FIREARM. If the property owner elects to, he can press charges (even though you are attempting to retrieve a downed game animal) for trespassing with the intent of poaching.
I know of several cases where this has happened. Matter of fact, several years ago as I was driving across my property one afternoon I noticed a pick-up parked across the fence next to my property. I had never seen the truck before and thought it strange that it was there. I dropped off a ridge, crossed a dry creek and started up the other side when I seen someone in one of my deer blinds. I drove toward the blind, the guy jumped out ran across the dry creek at a point I couldn't cross with my truck. I got out and shouted for him to come back, he turned and shot in my direction. I retrieved my SKS and started to pepper his butt good, but didn't. I jumped back in my truck and drove to the place I had seen the truck parked. I pulled into some brush, slipped across the fence and cut all four valve stems at the rim, went back to my truck and waited. After about an hour he came out. I asked him what he was doing, he answered "Just who the ^%$#@*& do you think you are and why are you asking. I explained I was the property owner, and that I had not given anyone permission to come on the property. (it was legally posted). I finally got his identification and had just finished writing his name and address in my book when I noticed another strange guy approaching, about that time I seen the third guy. Since the odds were in their favor, I ask them to leave in a nice way, jumped in my truck and left. I drove down to the nearest phone and called a game warden. Non was available, but when I told my story, they sent a county deputy out. He and I went back to find four of them by the out-of-commission pick-up. Their story, We crossed the fence looking for a deer we shot. Since they had been such a bunch of A$$ holes, I pressed charges. The judge finded them two thousand dollars each, they lost their guns, the tow bill on the truck was $300. And they could not get a Texas hunting license for five years.
If the guy had been half nice,most likely I would have let them look for their deer, or at least I would have just ask them to leave. But since there was no deer, one had shot at me (?) and the others gave me a hard time I wanted to set an example. Funny, the one that took the shot was named FINKE, he was a Chaplins Assistant at the local Air Force Base. THe guy that owns the property next to me caught some folks hunting on his property, he got the drop on them, chained them to a tree and called the game warren. He was in trouble for false imprisonment and they for trespassing, both dropped charges. But I'd bet after five hours at below freezing those boys will think twice before crossing someone else's property line.
Bottom line, in Texas, it's up to the land owner, but they can press charges if they desire. If it's POSTED, you sure don't want to cross the fence. By the way, in Texas, it is not necessary to have a POSTED sign. If the tops of every third-fourth fence post is painted PURPLE, it's the same as a sign. I suggest reading the Texas Parks and Wildlife Outdoor Annual (Hunting and fishing regulations) You should have recieved one when you got your license.