I have had a huge problem with four-wheelers over the past 5 years. This spring was the worst. I was coming out after a turkey hunt one day, just locked the gate and was driving to the main road, when a whole gang of about 15 four wheelers came bustin down the road towards me. I couldn't get out and fight 20 guys, so I just told em this was private property and to not ride here, which I've told em bunches of times. I can't gate off my entire property b/c the power company has to have access to the power lines, and they cut our lock a few years back to get in. We moved the gate back and now the riders can easily go down the power line and up a back road. We're working with the club next to us and the power company to put up one single gate with three locks for us all. I would keep my other gate up still. They were going around our gate for a long time, until I put up 3 strands of barbed wire with fluorescent flagging tape all over it (legalities). Then to deter them even more we cemented 4 lead pipes in the ground past the barbed wire so they wouldn't even be able to get by if they did cut the wire. Also found their exit path at the other end of the property, and I really had to search good to find it. They were being slick and coming in from another road, down the river's edge through the thick stuff and riding allll on my place. I was able to find this path and set 3 posts in the ground with a cable and pvc pipe nailed up between the posts with posted signs all over it. They haven't been back since. If they do, the sheriff and wardens have already been notified about this from me and the club next to us, so we should be able to keep em out, for now. All the advice I can give you, try to block off every single way they can get in. If you think you've found all the ways they're gettin into your place, look again, and then look once more, because trespassers are slick buddy.