On October 17, 2007, approximately 1515 mountain daylight time, a Cessna 210, N215MD, was substantially damaged when it impacted terrain following a loss of engine power while on final approach to Fremont County Airport (1V6), Canon City, Colorado. Visual meteorological conditions prevailed at the time of the accident. The instructional flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. The flight instructor and private pilot receiving instruction were not injured. The local flight originated at 1400. According to the flight instructor's statement, he and the student had completed their maneuvers and returned to the airport for a series of touch-and-go landings, in partial completion of a flight review. While on final approach for the fourth landing, the instructor noticed they had descended below the glideslope on the Visual Approach Slope Indicator (VASI). The student advanced the throttle to climb back onto the glideslope and there was no response from the engine. The student pumped the throttle and turned on the electric fuel pump without result. The airplane landed in a dirt field approximately 200 feet short of the runway. Examination of the airplane revealed the nose gear collapsed and the frame cross beam on the right side was cracked. An examination of the airplane engine by the Safety Board Investigator-in-charge and a representative from Teledyne Continental Motors revealed that the engine throttle cable rod had broken. Further examination of the throttle cable assembly, conducted by Cessna Aircraft Company under the auspices of the Federal Aviation Administration, revealed the throttle cable outer sleeve was cracked and had separated from the steel fitting. The end of the steel fitting was worn and deformed, and the swivel ball fitting at the end of the plunger was worn. The throttle cable was not a Cessna provided part. A placard on the throttle cable identified it as originating from Aircraft Components Inc. (ACI) of Benton Harbor, Michigan. ACI was a mail-order aircraft parts supplier, and ceased operations in 1990. Cessna recommends that all engine control cables be replaced at engine overhaul. A review of the maintenance records revealed the last engine overhaul was completed on November 2, 1989. The last annual inspection was competed on October 2, 2007. There was no entry in the maintenance records reflecting when the engine control cables were last replaced.