Our property starts about 3/4 mile from the pavement, at the end of a road which is used only for our access with minor use by the adjoining neighbors (2). Until a few years ago the road was generally unusable except by 4-wheeler, and sometimes only on foot. Whenever it WAS usable, because I or a neighbor cleaned it up for our own access, folks drove 1/2 mile in and dumped everything they could haul. We even found a dead horse melting into the woods just before putting up the gate.
Put up a good steel gate 2 years ago. They can't drive in with a pickup any longer, and are apparently unwilling to carry the trash far enough to dump it, so the problem has stopped. Nothing significant dumped by the gate. The road is also doing much better, as careless traffic would destroy the water bars which would let the rain destroy the road.