On August 17, 1993, at 1927 hours mountain daylight time, a Cessna T210L, N2125S, experienced a loss of engine power while on final approach to the Cheyenne Airport, Cheyenne, Wyoming. The flight was unable to make it to the runway and a forced landing was made to a field. During the landing roll, the airplane collided with a ditch and airport boundary fence. Visual meteorological conditions prevailed at the time and a visual flight rules flight plan was filed. The airplane was substantially damaged and the certificated airline transport pilot and pilot rated passenger were seriously injured. The flight had originated from Denver, Colorado, on August 17, 1993, at approximately 1845, as a pleasure flight. During a telephone interview and subsequent written statement, the pilot reported that when approximately five miles south of the airport, he completed the before landing checklist. The check consisted of switching the fuel selector to the right fuel tank, extending the landing gear, and adjusting the engine controls. The flight then entered the downwind leg for runway 12. Everything was normal until turning to final approach, when the engine quit. The pilot was unable to restart the engine and an emergency forced landing was made to a field. In the pilot's written statement, he reported that during the preflight check, water was present when drained from the right wing tank. The pilot stated that the fuel was drained sufficiently to ensure that no more water was present. The pilot also drained fuel from the two sump drains located under the fuselage and the engine compartment drain. The pilot did not mention the detection of water in any other area. During an engine inspection, it was found that the engine rotated easily with normal range compression developed in each cylinder. Rocker arm, valve train and accessory gear continuity was established. All spark plugs displayed normal operating signatures, and both magnetos sparked in firing sequence when rotated. Fuel was removed from the right header tank and the gascolator in the fuselage to check for contaminants. There were no noted contaminants found.