You can pay for a survey if you want to make sure.
Reminds me of my own property. My front yard is on a corner. Believe it or not people drove diagonally across my yard rather than drive to the corner and make the turn. I put huge boulders across my front yard. One day one of the boulders (about 300 lbs) at the driveway had been moved about a foot. There was a tire track on the driveway entrance leading to the boulder and pieces of plastic and glass on the ground. I laughed a lot, visualizing the possible scenario and wish I had a video of it.
So, to jchalas and friends, I agree with PayrolGuy, you know the rocks are there, drive carefully and avoid them.