A search for the aircraft was begun after the pilot's relatives reported it was overdue and residents near the crash site heard the sounds of a low flying plane suddenly terminate. Unofficial reports of the weather indicated it was about 200 ft obscured, 1/4 mi visibility with heavy snow, temp 30 deg, wind 200 deg at 5 kts. The aircraft was found in February 1983 by a cross-country skier. An investigation revealed it had crashed at high speed in a near vertical dive. The non-instrument rated pilot had not filed a flight plan and no record of a weather briefing was found. There were no communications with the pilot after he departed the Salt Lake City area. He had been assigned a discrete transponder code during departure and had not changed the code, thus a radar track was obtained. The radar showed a continuous track to the area of the accident, then was intermittently lost and remained in "bobs and weaves" until it disappeared. No preimpact/mechanical malfunction or failures were found.