All those rocks you found is one reason I chose the location of the first vineyard. I have stones on the farm, but not quite that big of a run, unless you just picked the bigger ones. Our area has been farmed a couple hundred years now so most of the bigger ones have been picked out. Many fields in my area have rock walls around them where the farmers picked the stones and made fencing out of them. Where I planted the vineyard, it was beach deposits from the ancient Lake Vermont, later replaced with an inland sea and then more recently Lake Champlain. There are no stone walls at this side of the farm where the beach was and yes, I feel blessed when I am working in that vineyard. The second vineyard has even fewer stones in it- three to be exact - LOL -(and those were carried into the field 20 years ago as part of a firepit my nephews built out of the brook a couple hundred feet away). The latest vineyard has the most, but only few dozen your size on 4 acres. Most of them are smaller than a baseball so they don't bother anything.