On March 15, 1996, about 1940 Pacific standard time, a Maule M-5-235C airplane, operated by the owner/pilot, collided with a tree during landing rollout near Sunriver, Oregon, and was substantially damaged. The private pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed and a visual flight rules (VFR) flight plan had been filed. The flight departed from Arlington, Washington, and was conducted under 14 CFR 91. The pilot stated that upon touchdown on runway 36, he felt a "tremendous tailwheel shimmy" and lost directional control of the airplane. The airplane began to veer off the right edge of the runway. The pilot stated that he applied full power to regain rudder authority. As the airplane headed back onto the runway, the right wing impacted a pine tree. The left wing then impacted terrain and the propeller contacted the ground. The pilot did not report any preimpact mechanical malfunctions. According to an FAA aviation safety inspector from Portland, Oregon, the right wing was substantially damaged in the collision with the tree, and the left wing and left horizontal stabilizer were damaged during ground impact. An examination of the tailwheel did not disclose evidence of preimpact mechanical malfunction. The pilot reported that he had logged a total of 154 hours of flight time, including 36 in type. The pilot estimated that the winds were at 340 degrees magnetic about 9 knots at the time of the accident.