During an IFR arrival at night, the pilot was cleared for the VOR Runway 27 approach to the Putnam County Airport. The published minimum descent altitude (MDA) for the approach was 1200 feet MSL or 437 feet AGL. Witnesses described the weather as 'foggy' with drizzle and 1 mile visibility. During the approach, the airplane struck trees that were about 60 ft tall and 1 1/2 miles east-southeast of the airport. An exam revealed that initial impact occurred with treetops on a heading of 315 deg in a wings attitude. No preimpact part failure was found. A mark on the airspeed gage indicated it was at the 140 kt position during impact. Both propeller blades had chordwise scratch marks and 'S' bending at the tips. The surrounding terrain at the airport was flat and sparsely populated. The aircraft was based at the airport, and the pilot had flown in the local area for several years. No records were found to determine the pilot's instrument flight or night flight proficiency.