I have never told anyone this, except my husband ( who never did believe me, he knows something happened but he can't wrap his mind around this possibility ) for fear of ridicule. I was alone when this occurred and I am finally reporting this incident 40 years later, more for my own piece of mind than for anything else. This memory is as clear today as it was the day it happened and still makes the back of my neck hair stand on end. Perhaps it will allow someone else to know that others are out there who've had an experience that can't be easily explained. This happened in Southern Illinois outside of the small rural community of Prairie du Rocher, a town that is over 200 years old. There is a great deal of wooded area, especially along the bluffs, large tree stands that follow along the Mississippi River and somewhat inland in very thick stands between the Illinois and Missouri bluffs, on up to the tops of the bluffs on both sides. It is a sparsely populated area. There is a great deal of wildlife there, a huge deer population exists and they are big and fat from all the corn and wheat fields. At the time of this incident we had horses which were being kept at a farm about three miles away from our house, up on top of the bluff on 17 acres of fenced pasture surrounded by woodland and cornfields. The land had a pond and several sinkholes, one which was present across from the old original French house which was vacant. This particular sink hole was approximately six feet deep in the center tapering up to about 2 feet along the edges. The inside of the hole had a profuse growth of young oak, maple and other hardwood trees that were approximately 4 to 5 years old and about twenty feet tall. ( The trees stood exposed out of the sink hole at a minimum of 12 to 14 feet in height.) The barn sat to the right of the house about 300 yards away and the horses were standing nearby. I had come up in late afternoon, probably sometime after 7 pm to the farm to feed and check on my two horses, and had planned to make camp between the house and the sinkhole and spend the night. I did not want to stay inside the house because of the fear of spiders and snakes. My husband was gone for the weekend and I wanted to get up early the next morning to go riding. I had my German Shepherd dog with me. I built my fire and put bacon on to fry and made a small pot of coffee. As the bacon was starting to sizzle inside my skillet I heard an odd grunt come from inside the sinkhole area close to the edge that was towards me, which was, at this point, approximately ten to twelve feet away from me. My dog was always ready to chase deer or any other animal away, but all he did at this time was stand close to me, then he started to shake violently. He wouldn't leave my side. I stood up and stared at the trees in the sink hole. I had no weapon on me. It was nearly dark by this time and the sound came again but this time it was a very, very loud screech, almost a scream so close I instinctively held my ears. My first thoughts were, did a bobcat smell my food, or a coyote? My mind was trying to rationalize the sound before I realized it was much too loud and strange for either animal to have made. Then, many of the trees began to violently shake back and forth, accompanied with more of the grunting, screeching, high and low growl sounds, I can't explain it any other way. It was as if someone or something had grabbed the trees in anger shaking them hard and rapid, I think in order to frighten me off. There was little to no wind only a slight mild breeze. Everything fell silent around me. My horses had come out of the barn, they had stopped feeding and were now staring at the sinkhole. I heard them stomp and snort before they turned and ran off at a fast gallop as if startled by a predator. I saw them from the corner of my eye but I kept watching the trees. I admit I was fascinated but there was a creeping sense of fear that filled me. Then the trees stopped moving. There was a faint odd smell in the air that didn't last long, and I did not recognize it. I only caught a whiff of it but I remember thinking how odd it was. Silence for maybe 5 seconds before another long sort or grunt sound came out from them. I didn't move, it was like I was rooted to that spot. The dog didn't move either. Then the trees started to shake again, the thing that got me was this time many of them were being shaken very hard! So many it boggled my mind, it just shouldn't be possible. I can tell you that the fear I felt then was unbelievable and it finally got me into action, I doused the fire and threw the hot skillet with the bacon still sizzling into the back of my pick-up got my dog and we left. I was still so frightened when I got to my home that I opened the outside cellar door and threw the skillet down the steps, grease, bacon and all. I wasn't able to clean things up for a couple of days afterward. The cellar floor was dirt and most of the grease had been soaked up when I finally was able to clean the pan up. I know it sounds stupid but I had been traumatized. Please know that I had been up at that farm many times all alone, riding, feeding, grooming my animals and was never afraid before, I never felt any fear from anything. I loved it. I would see many animals on my rides and I loved the woods. After this incident however, it changed my life, it scared me so much that we sold the horses and I stayed out of the woods. I have never been back in any woods or isolated place again! I didn't want to know what that was, and I never wanted to experience any of that ever again. Now I'm 63 years old, I was 23 when it happened. I've never forgotten nor have I spoke about it. This is the first time and I think from the length of this you can tell I'm still shaken up by the whole thing. Irrational? Yes, I probably think so, looking back on it I still remember how I felt, I still remember every detail. By the way, there was no mountain lions or bears in Southern Illinois at that time, still not that I know of, not where we lived anyway. Really no predator bigger than a bobcat, so what was this???? Even if there had been some type of larger predator what could it have been to have moved so many trees at one time and make that god awful noise?