On July 7, 1996, approximately 1345 mountain daylight time, a Beech A23-19, N5675S, was substantially damaged during a forced landing near Garfield, Colorado. The commercial pilot and private pilot-rated passenger were not injured. Visual meteorological conditions prevailed, and no flight plan was filed for the ferry flight conducted under Title 14 CFR Part 91. The flight originated at Pueblo, Colorado, on July 7, 1996, approximately 1300. According to the pilot, he departed Pueblo, Colorado, and climbed to 10,500 feet msl (mean sea level) and proceeded west. He said the ground was approximately 2,500 feet below. The engine was running smoothly and was "pegged" at 2,450 rpm. As he approached Monarch Pass (elevation 11,312 feet), the engine "popped twice" and engine power decreased 600 to 700 rpm. He applied carburetor heat, enriched the mixture, and lowered the nose to glide forward. The pilot attempted to land on U.S. Highway 50. As the airplane was flared, an approaching vehicle forced the pilot to pull up and bank sharply to the right. After passing over the vehicle, the airplane made a hard touch down on the highway. The nose and right main landing gears sheared off and the airplane collided with terrain. On September 18, 1996, the airplane and engine were examined at the facilities of Jensen Aircraft, Salida, Colorado. Substantial fuel was found in both tanks at the time of retrieval. The fuel screens, fuel lines, and carburetor were checked for contaminants. None were found. The carburetor bowl was full of fuel. No evidence of water was found in the fuel. The carburetor heat, throttle, and mixture controls worked properly and all of these controls contacted their stops. The air filter was clean and free of obstructions. All spark plugs fired normally when tested. There was continuity of the spark plug leads. Both magnetos fired normally and were properly timed and grounded. The engine was then functionally tested and operated normally. At 2,250 rpm (revolutions per minute), fuel pressure (without the electric fuel pump operating) was 2.5 psi (pounds per square inch). Maximum rpm obtained was 2,350 rpm. When the magnetos were tested at 1,800 rpm, the maximum drop was 75 rpm. The engine idled smoothly at 650 rpm. Cylinder compression check after the functional test was as follows: No. 1 - 76/80; No. 2 - 72/80; No. 3 - 70/80; No. 4 - 70/80. A Jensen Aircraft spokesman said that the pilot had told him he had flown over Salida Airport at 8,200 feet msl. The summit of Monarch Pass is 11,312 feet msl (a difference of 3,112 feet), and is 17.5 miles west of Salida. According to a Beech Aircraft Company spokesman, if the pilot maintained the best rate of climb airspeed of 70 knots, the airplane would be capable of climbing 270 fpm (feet per minute) at 8,000 feet. Thereafter, the climb curve drops abruptly and at 12,000 feet, the airplane would be capable of climbing only 50 fpm. These figures are based on the meteorological conditions that prevailed (as reported by the pilot), and a computed density altitude at Monarch Pass of 15,061 feet msl. The pilot told the Jensen Aircraft spokesman that he flew directly to the pass and did not circle in an attempt to gain altitude.