Keep driveways and landscaping well maintained so that all visitor traffic is funneled to the house or another desired location so that you can confirm visitor identity and the purpose of the visit. This will help restrict unauthorized access to facilities on the farm or ranch. Consider putting up screens such as high fences, tall hedges, and trees along high-traffic roads. Keep an aggressive farm watchdog.
Consider installing an electric eye or camera to detect and announce visitors entering the farm or ranch site. Installing an electronic monitoring system (i.e., motion detector) is also an effective way to keep watch over your farmyard and equipment. The system should be wired to the house or shop and connected to a computerized farm monitoring system.