When I was about 12yo, I was out on a dove hunt with my father, brother, and uncle. We would camp in the same area, every weekend, every season. So, we were familiar with the area and picked camp sites that didn't bother the local's, while keeping us close enough to town for supplies.
One morning, we decided to drag our feet to get ready for the morning hunt. While eating breakfast, my father was outside the trailer, glassing over the nearby river (scouting ahead for duck season honey holes). He just happened to catch a glint out of the corner of his eye and realized there was a vehicle about 1/4 mile from our campsite. It was uncommon to have anyone come out towards us, since we camped outside of town. When he turned his binoculars toward the vehicle, he saw a man standing with his door open and a rifle wedged between the door and pillar...pointing it at him/us. Needless to say, my father yelled to us, ran to the truck, and grabbed his .45 . My uncle grabbed his Judge and sat by the door, while my father raced his truck toward the vehicle.
As he closed the distance, he saw the man jump in his truck and tear off. Unfortunately, he didn't catch up to the guy, but he got close enough to get a license plate number and reported everything to the local sheriff. About an hour later, the sheriff came out and said he tracked the guy down, but couldn't do anything. Apparently, the guy told the sheriff he was "using the scope to see who was camped" and that he "didn't know anyone was at the campsite."
We never saw that guy or his truck again and continued to hunt that area for years. We did, however, end up buying a house in the nearby town to have a safer place to stay during our hunts.