Report 71792: Chatter and knock heard on the Broad River, 5 miles NE of Gaffney

I was camping with my stepdaughter and one of her friends at the Big Bay Access Area on the Broad River.  Upon arrival at the campsite at 12:30 AM, as is our custom, my stepdaughter did a 2-3 second howl and I did a heavy growl.  Immediately thereafter, we heard creature chatter from across the parking lot (100-150 yards away), followed seconds later by a wood knock from the same direction but further away.  I found a large stick and answered with two wood knocks, but got no response.