Report 21977: Possible Wood Knock Interaction at Wildcat Ridge near Rockaway

My wife and I were hiking at Wildcat Ridge Wildlife Management Area in northwestern New Jersey on the afternoon of March 11th 2006. We were heading towards the hawk lookout when I began to hear what sounded like wood knocks coming from behind us to the east. I decided to knock back to see what would happen. I had my Panasonic Digital IC recorder model RR-US360 with me. I knocked while my wife recorded. This happened at approximately 1:30 PM in the afternoon. I have been hiking this area for a few months now and have come across some interesting stick structures. I later found out from a neighbor that lived in the area his entire life that there are caves and mines on the side where the knocks were coming from. Could it be Sasquatch? I do not know for sure, but I cannot think of anything else making these wood knocks and stick structures.