On August 17, 1996, at 1530 central daylight time, a Cessna 172, N6218F, operated by a private pilot collided with trees after running off the end of runway 36 (2,100' x 100', grass) at the Galt Airport, Greenwood, Illinois. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions without a flight plan. The airplane was substantially damaged. The pilot and passenger were not injured. The flight originated from the Galt Airport, 1320 cdt. The pilot stated that he took off on runway 09 (hard surface) then entered a left hand traffic pattern to land on runway 36. He stated that while on final approach, another airplane departed on runway 09 crossing in front of him. He stated that he was a "little high" at this point so he retarded the throttle and extended 40 degrees of flaps. He stated that the airplane touched down about 1/2 way down the runway and bounced twice before settling on the runway. He stated he applied full brakes, back pressure on the yoke and retracted the flaps; however, the airplane continued off the end of the runway. The airplane traveled into an area of high brush with the wings contacting 6 to 8 inch diameter saplings.