Report 31439: Possible rock throwing display while night fishing at Salt Fork State Park

Back in 2010 I and a friend were at Salt Fork Lake fishing at about 9:30 p.m. That evening we heard some banging of trees and the next thing we know rocks as big as my fist were bouncing off the ground. After 6 or 7 of them we grabbed our stuff and left. We never saw what it was but the rocks were being thrown from a great distance. I'm 6' 3" and 260 lbs, and there is no way I could of thrown these rocks any distance.