Something walking upright in Butler County, Pennsylvania

At approximately midnight I was traveling home from my parents, I got about 3 or 4 tenths of a mile, going slowly up a steep grade, I saw something out of the corner of my eye, assuming it was a deer about to cross the road in front of me I stopped. Well it wasn't a deer, when I first looked at it I thought maybe it was a bear walking upright, but when "it" got directly in front of my headlights I couldn't believe my eyes! It was NOT a bear! It walked ever so slowly across the road like the car wasn't even there, did not even look my direction. I was so scared, (my little girl was sleeping in the back seat) I thought I should just step on the gas and try to hit it, all kinds of ideas were racing through my head, but I decided not to try to run over it cause I thought if I just hurt it and make it mad it might hurt me and my daughter. I'm sure it was probably only a minute but it seemed like a lifetime until it crossed the road and was gone. It made no sound. It resembled very much the pictures at this site. I have never spoken of this publicly, and have only told very close relatives. I had nightmares for years afterwards. A few years later my mother and my daughter were walking through an old strip mine just a short distance from where it had crossed the road years before, there were fresh footprints in the mud! I believe my brother made a plaster cast of the print. (We don't speak any longer so I'm not sure if he still has it). I originally saw this thing in 1977, my mom saw the prints about 5 years later. So obviously it was still around the area. My parents have passed away, and the area is now much more populated.