On September 25, 1994, at 1620 central daylight time, a Cessna 180, N9425C, was substantially damaged during a forced landing near Denton, Texas. The airplane, owned and operated by the airline transport rated pilot, was on a personal cross country flight. There was no flight plan filed and visual meteorological conditions prevailed. The pilot received minor injuries while the three passengers were not injured. According to the pilot, he experienced an complete engine power loss while on base for landing at his home airport after the cross country flight. He determined that he could not glide to the runway and set up for a forced landing to a dirt road located about 1/4 mile short of the runway. On short final, the pilot spotted power lines and executed a shallow climb to clear them. He said that the resultant loss of airspeed induced a stall and the airplane impacted the ground. Examination of the airplane revealed that 5 gallons of fuel was present in each tank. The pilot reported that he thought a tank unported when he applied 20 degrees of flaps during the approach. The airplane flight manual indicated that 2.5 gallons of fuel per tank were unusable, except for level flight.