Report 1815: Hiker encounters intimidating beating sounds and heavy running footsteps

In early May 2000, I had decided to go hiking in an area which is closed between November and May 1st. On previous hikes and camping trips in the area I had noticed a trail and on this day I decided to see where it went. I stopped my car, and upon getting out noticed that the area was silent; no birds, frogs,or other animals were calling out, which I found odd. I had started up the trail(approx 1/8 mile) when I heard(and felt) what sounded like someone pounding on a hollow tree in an incredibly fast and hard manner. The sound was coming from my left and I guess it was maybe 1/4 to 1/2 mile away. Approximately 10-15 seconds later, I heard the same type of noise more to the right and closer. I would say within 200 yards. I could feel the percussion as well as hear it. I continued walking uphill along the trail for another five minutes when I encountered an odor that I had never smelled before. I did note the breeze was in my face.I continued for another 40 yards when something started walking/running rapidly through the brush approximately 20-30 yards ahead of me, moving from my left to my right. Every time it stepped, I could feel it through the ground, so whatever it was was big. I immediately took a trail to the left that led downhill, as I thought I may be cut off on the trail I was on, and I didn't want to get in anythings way if it was coming down the trail I was coming up. Whatever it was then moved from my right to my left through the brush as though to cut me off on this trail as well. I then started running to my left diagonally through brush and deadfall to try and cut the trail I came up on. I did cut the trail and ran back to my vehicle. Whatever was there did not follow me down to my car, nor did I ever see it. Upon reaching my car I again heard the same drumming noises, this time the second one was much closer and uphill of the trail I had started on.