Man and witnesses have two seperate sighting, 1st while fishing, 2nd while driving

In April 1982, the witness and a companion were driving home from their senior prom late at night on a flat road section. Under the car headlights they saw a massive black-furred creature leaning on a road sign, with about ten feet of its chest-down visible but no head in view. Terrified, they sped up and continued driving; about a mile later a tire blew out, and they drove several miles to a house to call for help.