Report 41907: Memory told of a possible sighting at night in a pasture east of Jacksonville

It was winter in 1986-87 in Central Illinois, Morgan county, just 3 miles east of Jacksonville off the old state road. Myself and another friend were riding a 3 wheeler in the snow thru a pasture area along a creek and wooded area about 11-1130 PM. We were taking turns riding it and while 1 was riding the other would wait for the rider to come back. 1 of the times while I was riding aprox 200 yds off the road, I spotted a bigfoot aprox 7 ft tall and probably 400lbs. It was walking across the narrow part of the pasture aprox 30yds wide from one stand of woods to another, This part of Illinois is all farmland with a lot of creeks and rivers but not an extreme amount of woodland, my only thoughts were that what the heck had I just seen...