Sometime about 1977 I lived back east, and my Brother was in north New Jersey. We took four of the kids to Newberg NY to fish the Hudson south of the bridge. It became rainy and blustery so we motored to an island with the remanants of an old stone castle.
Went ashore and found the ground littered with small metal parts. Many were sights and trigger parts. It was the Bannerman Arsenal. He shipped in and out by boat. Two of the kids got poison ivy which was all over.