On July 29, 2000, approximately 1400 Pacific daylight time, a Piper PA-32-300, N934PH, registered to an individual, operated by Kennewick Aircraft Services, Inc., and being flown by a private pilot, sustained substantial damage during an in-flight collision with several fence posts during a balked landing at a grass/turf landing site near Birkenfeld, Oregon. The pilot and passenger were uninjured. Visual meteorological conditions existed and no flight plan had been filed. The flight, which was personal, was operated under 14CFR91, and originated from Kennewick, Washington, approximately 1300. The pilot was telephonically interviewed and reported that he and his wife rented the aircraft at Kennewick and intended to fly to the Holce & Oblack private airstrip located approximately one nautical mile south of Birkenfeld. Upon arrival, the pilot determined that the destination airstrip had not been mowed and chose an alternate landing site at his father-in-law's residence a short distance northeast. He reported that this grass field was approximately 1,650 in length. The pilot stated (NTSB Form 6120.1/2 attached) that he intended to execute a "Landing West to East, taking advantage of the uphill grade of the field" and that he "allowed the plane to float using too much ground roll for roll out." He continued, stating that he applied "full throttle for a go-around" and "had the fence made on the East end of the field except for three posts. The right landing gear struck the top of a fence post almost even with the center of the tire." The pilot was able to continue the climbout and re-entered the downwind for landing. While in the pattern he noted the separated right landing gear (wheel and strut) lying in the field. He then executed an easterly landing in the intended field. The pilot reported that there was no mechanical malfunction with the aircraft during the event. Post crash examination revealed that the right main landing gear had separated from the aircraft and had impacted the leading edge of the right stabilator (refer to photograph 1). The left wing underside, approximately 30 inches inboard of the tip, displayed upwards deformation and skin tearing (refer to photograph 2).