At 0928 eastern time a Mooney M20C crashed into trees while the pilot was searching for a private grass strip in Monticello. The pilot was killed. Instrument conditions prevailed at the time, but the flight was not operating under IFR. A witness said the weather was foggy and he heard the airplane but could barely see it as it flew over him at low altitude. Another witness said he had been waiting for the pilot to meet him at his private airstrip about a quarter mile from were the accident occurred.