On July 4, 2019, about 1145 central daylight time, a Cessna 140 airplane, N3725V, was substantially damaged during a nose-over during a precautionary landing near Reeves, Louisiana. The pilot was not injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not on a flight plan. The flight originated from the De Quincy Industrial Airpark (5R8), De Quincy, Louisiana, about 1120 with St Landry Parish Airport-Ahart Field (OPL), Opelousas, Louisiana, as the planned destination. The pilot reported that he landed at 5R8 to get fuel and to take a break. He stated that he also filled the engine oil at this time. About 15 minutes after departing 5R8, he noticed that the engine oil pressure reading had dropped to about 0 pounds per square inch (psi) from 30 psi about a minute earlier. Using his electronic flight charts, the pilot determined that the nearest airport was 7 minutes away. Due to the wooded area over which the airplane was flying, the pilot elected to make a precautionary landing to a clearing nearby. During the precautionary landing the airplane's right wing strut struck a fence post, the airplane bounced a few times, and nosed over. The airplane had substantial damage to the right wing strut, the vertical tail surfaces, and the engine mount. After examining the airplane after the accident the pilot found the oil dipstick loose from its proper location.