we have the same problem with 4 wheelers coming onto our property. Tresspassing signs just dont seem to work for the rednecks out here. I got a 1"x6"x8', put 4 inch nails through it, put it right under the surface of thetrail they were usingabout 10 feet intoour property. A week later i went out and found the board alll broken to pieces but they havent come back on the property since then, or atleast not that i know of. They quickly learn thatcoming onto or chasing game onto our propertyisnt worth the cost of blown out tires