Growling in Lee County, Alabama

One evening my wife and I decided to go to my hunting club property to a place where we used to go sit and talk. We got there just before dark and had been there for several hours when it happened. The place where we were is on a large power transmission line right of way.There is a small stream that crosses the clearing, and a very steep hill on the side where we parked. In fact, so steep that it is difficult to drive a four wheel drive down to the stream. On the other side of the stream there is a low level spot that then becomes another steep hill. I would say that the hills are a good 50 feet higher than the stream. I had parked my truck on the hilltop, and we sat on the tailgate facing the stream. Around 11:00 pm we heard a very loud snorting noise coming from the bottom of the hill, and the sound of brush moving and breaking. I thought that it was a wild hog, because they are plentiful in this area, so I told my wife to get in the truck, because I was afraid it would attack us. She got in the truck while I tried to find my flashlight and my gun. When she slammed the door, I heard a loud, low growl/grunt and it sounded like something large started running up the hill towards us. I was standing in the bed of my truck by now trying to shine my light down the hill, but the batteries were weak and I couldn't see very far.There was a very bright moon out so I turned off my light, and could see a large shadow moving around about halfway up the hill towards us. I was listening to it move around and make the same growl/grunt noise. I could also hear what sounded like breathing noises. I then caught scent of a strange, musky, sour odor and heard more brush breaking and what sounded like stomping noises. I was certain by now that this was not a wild hog, but couldn't figure out what it might be. So I told my wife to start my truck and rev the engine a few times and when she did, I heard what sounded like something crashing through the brush heading down hill and moving fast. We were both a little spooked by now so we left. As I pulled out onto the dirt road off the power line trail, I turned toward the bridge that crosses the small stream (the road roughly parallels the power line) a large number of deer ran at high speed across the road,heading away from the stream. I tried to convince myself that it was just deer that I heard,but couldn't explain the shadow I saw.