On October 5, 1996, approximately 1439 eastern daylight time, a Maule MX-7, N6124Q, was substantially damaged when it impacted trees during takeoff from Mahopac Airport, Mahopac, New York. The certificated private pilot/owner and the passenger were uninjured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot stated that they took off from Danbury Municipal Airport, Danbury, Connecticut, approximately 1400, and flew directly to the private grass strip at Mahopac. The runway at Mahopac was oriented north/south and was 1,800 X 150 feet. The private pilot stated that he completed two full stop landings to the south, and then shutdown the airplane for a brief stop. On startup, the pilot noticed that the active runway had changed to the north, and stated that he had never taken off or landed in that direction. He taxied to the south, completed the takeoff checklist, and added 24 degrees of flaps. The pilot stated, "as I fully opened the throttle, I held back-pressure and some right rudder to maximize tail-wheel steering." The pilot also stated that, "the south end of the field was much rougher than he expected, and after a strong bounce, the airplane remained airborne in ground effect". The pilot stated that he focused on the airplane's lack of acceleration, and did not see the group of saplings until they "loomed" in the windshield. With the airspeed too slow to climb, the pilot stated that the airplane impacted the trees in a wings level attitude less than 10 feet off the ground. The pilot depicted the runway with no centerline markings and sloped uphill from the south to the north end of the runway. The measurements taken of the accident showed the airplane traveled a distance of 700 feet down the runway and drifted left more than 75 feet into the saplings. The pilot stated that he had no mechanical problem with the engine nor with the airplane's flight controls. Winds at an airport 18 miles to the south of Mahopac were reported to be from 130 degrees at 8 knots.