On July 28, 2010, about 1125 Pacific daylight time, a Piper PA-28-180, N57PJ, collided with terrain during an off airport forced landing 32 miles northeast of Walla Walla, Washington. The private pilot operated the airplane under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. The pilot was seriously injured. The airplane was substantially damage by impact forces. The local personal flight departed Martin Field, College Place, Washington, about 1000. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot stated that he was going to conduct a local scenic flight and that he took a Dramamine prior to takeoff in anticipation of turbulence over the mountains. During preflight, he noted that both wing tanks were filled to the tabs, and he took off with the fuel selector on the right tank. He climbed to 10,000 feet, and proceeded on his flight. At 1030, the pilot reported an anomaly with the airplane to air traffic control and declared an emergency; however, he was unable to determine the problem. In the NTSB Pilot/Operator Aircraft Accident Report the pilot stated that his last memory of the flight was when he reported 10 miles east of the Walla Walla Airport at 10,000 feet. He has no recollection of any of the events between that position report and Saturday, August 1st. Air traffic controllers from Walla Walla Regional Airport (ALW) reported that the pilot stated he was at 10,600 feet mean sea level (msl) inbound from approximately 10 miles north of Walla Walla, experiencing some type of difficulty. The pilot was advised to continue inbound to Walla Walla. The controller reported that during the next 60 minutes he attempted to determine the nature of the emergency. After numerous requests, the pilot stated that it may be an electrical problem. According to the approach controller, with each successive pilot transmission, the pilot's voice was sounding more unsure and his speech rate was slowly deteriorating and uneven. The controller advised the pilot to open vents and windows. Shortly after the last communication with the pilot was made, the controller received notification of the downed airplane. Radar track of the airplane revealed a normal ground track from southeast of Walla Walla to northeast Walla Walla. The airplane then proceeds to meander making circular patterns. The airplane departs the area and has a zigzag-like flight path to the area of the crash site 32 miles northeast of the Walla Walla airport. A witness who saw the airplane land stated that while landing the pilot fully stalled the airplane just above a wheat field. The airplane struck the ground extremely hard and nosed over. When the witness arrived on scene the pilot was unconscious. The witness also noted that he did not notice any gas leaking from the wings nor a smell of gas. An on-scene examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed the fuel selector valve was on the right tank. The tank was not breached, and it did not contain any fluid/fuel. He observed that the wing spar and fuselage sustained substantial damage. The inspector further reported that there was a lack of a smell of fuel, and there was a lack of damage to the propeller blades. A letter dated September 7, 2010, was received by the FAA Northwest Mountain Regional Medical Office from an attorney representing the pilot. The letter stated that for personnel reasons the pilot was surrendering his medical certificate.