On June 13, 2002, at 1000 central daylight time, a Piper PA-32R-300, N38709, piloted by a private pilot was substantially damaged following impact with trees on takeoff roll from runway 18 (2,400 feet by 80 feet, turf) at the Beaumont Hotel Airport (SN07), Beaumont, Kansas. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 91 personal flight was not operating on a flight plan. The pilot and two passengers reported no injuries. The flight was originating at the time of the accident and was en route to Eureka Municipal Airport (13K), Eureka, Kansas. The pilot reported that it had rained the day and night before the accident, and that he inquired about the condition of the runway prior to his departure. The pilot stated in a written statement, "No one expressed any conern about the runway. I was reminded that there was a big event there the previous weekend with about 40 aircraft coming and going. I made mental note of that." The pilot stated in a written statement, "I did the engine runup and set takeoff flaps and trim while taxiing. I kept the aircraft rolling at the north end of the runway as I turned south and applied takeoff power. Prop was full increase, mixture was full rich. The airplane was slow to accelerate. The airplane was going about 50 knots when I hit the last 500 [feet] of the runway where it is more steep. I figured the airplane would accelerate more easily at that point and take off. It did not. Instead, I ran into some mud which kept the airplane from accelerating. I tried to get airborne. The plane was just clearing the ground with the left wing hit a tree and the right gear hit a power pole laying on the ground. The airplane settled back to the ground and slid about 300-400 [feet] in the mud coming to rest against a railway berm." The pilot reported that he, "...should have been more quick to recognize the failure of the plane to accelerate and should have aborted the takeoff." No anomolies with repect to the airframe, powerplant, or systems were determined to have existed prior to impact.