The pilot reported that the airplane departed with 39 gallons of fuel, and about 1 hour and 40 minutes after departure the engine lost power. He adjusted the fuel mixture and throttle, with no effect. While maneuvering for an off-airport landing, the left wing impacted a pole and rotated the airplane counterclockwise. Subsequently, the nose landing gear collapsed and the airplane came to rest in an open field. The airplane sustained substantial damage to the engine mount, fuselage and both wings. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The sheriff's deputy, that responded to the accident, observed that there was fuel pouring out of the left wing of the airplane. The Federal Aviation Administrator inspector who examined the airplane reported that the fuel selector lever was on the right tank selected position. The right wing tank contained about 8-10 oz. of fuel remaining with no visible signs of leakage. Upon removal of wing to fuselage lower trim panel it was noted that the vent line and fuel supply lines were intact and secured. The left wing tank contained about 4.5 gallons. Visual evidence of fuel seepage stains were observed on forward part of pilot door. The inspector further added that the overall engine condition was good.