On January 13, 2002, at 1445 Pacific standard time, a Cessna 150M, N704NY, registered to and operated by Zephyr Aviation Ltd., as a 14 CFR Part 91 instructional flight, experienced a loss of engine power while in cruise flight. The student pilot initiated a forced landing to an open field near Clinton, Washington. During the landing roll, the aircraft collided with a fence. Visual meteorological conditions prevailed at the time and a visual flight rules flight plan was filed. The aircraft was substantially damaged and the student pilot was not injured. The flight originated from Bellingham, Washington, at 1400. In a written statement, the pilot reported that prior to departing from Tacoma, Washington, for the round robin flight to Bellingham, he checked the fuel level by looking in the wing fuel tanks and then sticking his finger in the filler hole where he was able to touch the fuel and approximating that they were about 3/4 full. The pilot then took off for the flight to Bellingham. The pilot reported that he stopped at Bellingham to use the facilities. The pilot then began the return trip without fueling the aircraft. About 45 minutes after departure, the engine quit. The pilot reported that he attempted to restart the engine without success. The pilot initiated a forced landing to an open field. During the landing roll, the right horizontal stabilizer collided with a fence post. Federal Aviation Administration Inspectors from the Seattle, Washington, Flight Standards District Office and maintenance personnel from Zephyr Aviation responded to the accident site. During the on-site inspection, the left fuel tank was found empty and the right fuel tank contained a small amount of fuel. The fuel strainer contained approximately 3/4 cup of fuel, and the carburetor bowl contained about 1/2 cup of fuel. Fueling records and Zephyr's Aircraft Rental Flight Log indicated that the aircraft was last fueled on January 10, 2002. A 2.2 hour flight was accomplished on January 11, 2002. No fuel was added after this flight. The accident flight flew another 1.6 hours for a total of 3.8 hours flown since the last fueling. The Cessna 150 Owner's Manual indicates that the standard fuel tanks full volume is 26 gallons, with 22.5 gallons useable. The pilot's flight planning log indicated that he estimated using 13.2 gallons for the 212 mile round trip flight, and about two hours and twenty minutes of flight time.