Untitled Sighting

I was walking around late one nite b/c I could'nt sleep. I decided to walk up to a railroad crossing were I walk to all the time. When I got up to the crossing I heard this very loud scream that I had never heard looking around but could'nt see anything. I heard the scream again & it sounded like this thing was thrashing around in the trees & bushes, very loudly too like it was breaking trees over & felt like it was no more than a few feet away but still it was dark & I could'nt see anything, All of the sudden I started hearing these thuds around me I look down & start seeing these rocks landing around me it was then I looked up & seen this rock coming through the trees & landing right by my feet. This rock was bigger than a softball but smaller then a basketball, so I pick up a rock & through it back into the woods were the last rock came from. When I done that, this thing started thrashing around & started screaming again even more than before so I decided it was time for me to leave so I took off back down the road. when I got down to the main road which I just live across the other side of it. I hurd this thing screaming all the way up the mountain. I think that I had walked up on this thing & startled it.