On December 23, 1997, at 1916 mountain standard time, a Cessna 172M, N1596V, operated by Vista Air, Whiteman Airport, Van Nuys, California, collided with power lines while maneuvering near Monticello, Utah. The private pilot received fatal injuries and his passenger minor injuries. The aircraft sustained substantial damage. No flight plan was filed for this cross-country flight operating under Title 14 CFR Part 91 and the last known departure point was Cortez, Colorado. The originating airport was Whiteman Airport, California, and the reported destination was Grand Junction, Colorado. After departure from a fuel stop at Cortez, where 13.8 gallons of fuel was purchased, the pilot contacted Denver Air Route Traffic Control Center (ARTCC) when approximately 20 miles north of Cortez, and requested assistance due to his being disoriented. The Center could not acquire the aircraft on radar and requested the pilot climb the aircraft until radar coverage could be achieved. (The floor of radar coverage in that area was approximately 2,000 feet above ground level). The pilot failed to climb the aircraft to a sufficient altitude to gain radar assistance, thus communications with the aircraft was lost. At 1840, a San Juan County, Utah, Deputy Sheriff noticed an aircraft circling the city of Monticello. At 1916 the aircraft struck two sets of power lines 1/2 mile east of the city. The first power line carried 345,000 volts and the aircraft struck this line 63 feet above ground level. The second line carried 138,000 volts and the aircraft struck this line 55 feet above the ground. The power lines were oriented in a north to south direction and the aircraft was on an westerly heading at the time the power lines were contacted. Information provided by Denver ARTCC revealed the accident aircraft and the aircraft they had attempted to assist bore the same registration number. After the aircraft struck and severed the power lines, it impacted terrain approximately 225 feet west of the lines. Wreckage orientation and witness marks provided evidence the aircraft impacted the ground in an inverted position. Witness marks provided additional evidence that the engine rotated approximately 90 degrees rearward during impact and the rotating propeller entered the cockpit area and struck the pilot in the head. The power lines exhibited multiple strike marks and the propeller bore severe leading edge damage from impact with a metallic object. Investigation revealed the pilot had 63 hours total flight time 3.2 hours of which were at night. His private pilot certificate was issued on December 13, 1997, and he had no previous flight experience in the area where the accident occurred. The pilot had rented the aircraft from Vista Aviation, Inc., Whiteman Airport, Los Angeles, California, d.b.a. Vista Air, on December 22, 1997, at 2130 with the intent to return the aircraft on December 23, 1997. His listed destination was Grand Junction, Colorado. Toxicology results on the pilot were negative for carbon monoxide, cyanide, and ethanol. Ephedrine and Phenylpropanolamine were detected in the urine. According to the NTSB flight surgeon, these are "over the counter" medications used as a cold remedy and/or stimulant and are not considered as disqualifying. The Monticello airport is located 3 miles north of the city and is lighted by pilot activated lights. Communications with the airport is UNICOM on VHF 122.8 megahertz. There is a rotating beacon on the airport which operates from dusk to dawn. The beacon was functionally checked on December 24, 1997, in both the override and photocell automatic modes, and was found to operate normally. According to information provided by an NTSB meteorologist, official sunset was 1710 and the end of twilight was 1740. Moon illumination was 30%. Witnesses provided information that the weather was clear skies with good visibility. The ground was covered with several inches of snow. Investigation by the Sheriff's department in San Juan County, Utah, revealed two packages of marijuana with a total weight of approximately 200 pounds in the back seat of the aircraft.