On July 7, 2001, approximately 1030 Pacific daylight time, a Piper PA-24-250, N7994P, registered to and being flown by a private pilot was substantially damaged during an on-ground collision with trees and a deer during landing roll at Vaughan Ranch Airfield, near Fragaria, Washington. The pilot was uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was personal, was operated under 14CFR91, and originated from Boeing Field, Seattle, Washington, about 1020 on the morning of the accident. The pilot reported that upon arrival at the Vaughn private airstrip he entered the traffic pattern for landing. He further reported that, "...Upon aligning with the runway [02], I lowered full flaps and verified that the runway was clear...." The pilot slowed his approach speed to 85 miles per hour, adjusted his glide slope to clear the trees at the approach end of the 2,200 foot long grass runway, and touched down about 200-300 feet beyond the displaced threshold. He continued reporting "I...saw a deer standing slightly right of centerline at approximately 1/3 to1/2 way along the length of the runway...." The pilot chose not to attempt a go-around maneuver on the unidirectional runway because of the upsloping runway and tall trees at the north end. The pilot further reported, "...I applied full brakes and watched the deer turn to look my direction then look away but it remained standing in the same spot. The deer was too close to allow the aircraft to stop in time and was facing slightly to the right so I maneuvered to the left side of the runway trying to avoid collision with the deer. The airplane continued to the left until the left wing and landing gear contacted an embankment on the left side of the runway...." The aircraft was traveling about 30-40 miles per hour when it ground looped and came to rest along the left edge of the runway. The pilot reported that the runway width was 50 feet with an approximate 25 feet additional surface outboard of each side of the runway. He also reported that there were tall trees on either side of the runway and at the runway's north end.