Report 30530: Late afternoon sighting of a road crossing on Hwy 52 north of Dubuque

On Aug 31st I was on my way home from work in Richardsville, Iowa. There has been lots of road work on this HWY 52 North so I wasn't expecting to see anything out of the ordinary which is typically deer,coyote, or a fox on a rare occasion. I was just about 10 to 15 min north of Sageville, IA on 52 north when to be coming around one of the curves of this winding road when I saw a dark figure in a forward lunging position running at the same time leap over the guard cable and as i was passing that very spot I could clearly see its dark shorter hair and its shoulder and upper arm as if being lifted to clear the thick bushes. I pulled over and turned around at the next driveway and stopped and ran back to that point of entry but by that time it was gone! no noise so it may have found cover quickly and I couldn't see it. it appeared to approx 6ft tall and well built upper body and very thick muscular legs. its head was long and cone shaped. It looked to weigh around 300 pounds or so.I returned the next day but found no prints. was too thick to get into and see. this was around 5:15 to 5:30pm in the early evening.