Growling in Houston County, Minnesota

It was late October 1975. I was coon hunting on a beautiful, still, and moonlit night. I was walking along a picked corn strip at the wood line, along the top of a ridge. My two coon dogs were hunting out ahead. I heard my old dog bark a few times, then come running by me with her tail tucked under. The other dog was young, but not afraid of anything. Where the old dog came out of the woods, he went in. With a loud, savage bark and growl, he came out also and stayed by me, leaning against my leg growling and quivering. It was then that I heard a very low, moaning-type sound which was very audible. I shined my light down into the woods, but could not see anything as the land dropped off rather steeply into a large wooded ditch, maybe 200 feet deep. It was then that I heard what is best described as a large rock being thrown and bounced into a brush pile. I hollered, "whose there"! Then it sounded like someone hitting a hardwood tree with a club, twice. I then backed up myself, with my dog still looking down hill growling and never leaving my side. I could hear whatever it was moving down the steep hillside in the leaves and up the other side. That definitely ended my hunt as the dogs would not hunt there anymore. About two weeks later, after our deer season hunt was over, I saw a friend of mine and asked how his deer hunting went. He hunted on the very same land I was on. Usually his party killed many deer. However, he said something was really strange as they never saw any deer at all. Also, the property owner's cattle would not leave the farm buildings. I have always remembered this experience. While watching television at a friend's house, I watched your show. When you mentioned the "hitting tree sounds" it rang a bell in "this old man's head." Could it have been a Big Foot or not? I don't know, but I just had to write about my mystery.