At about 1750 Pacific time, a Cessna 172N nosed over during a precautionary landing about 11 miles east of Madera. The private pilot was not injured. The pilot said he had been flying more than an hour when he became uncertain about his location and noticed it was getting foggy. He decided to make a precautionary landing. The pilot landed on a 650- to 700-foot airstrip used for radio-controlled airplanes. The airplane overran the strip and struck a berm. Responding law enforcement officers reported there was no fog in the area and that visibility was unrestricted. Other nearby airports reported clear skies and visibility of 10 miles. The accident happened right at sunset.