On August 13, 2004, approximately 0700 mountain daylight time, a Cessna 172P, N6249K, piloted by a private pilot, was destroyed when it impacted trees and terrain while maneuvering approximately 20 miles east of Spanish Fork, Utah. Visual meteorological conditions prevailed at the time of the accident. The local personal flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot and three passengers on board the airplane were seriously injured. The flight originated at Spanish Fork approximately 0530. According to the pilot's accident report, and corroborated in a conversation with his father and an FAA investigator, the pilot sustained "major head trauma" and could not recall any details about the accident. The following is based on a conversation with the passenger in the right front seat and a Cessna Aircraft investigator: They took off approximately 0530 with what he believed to be full fuel tanks (flying club policy was to fill the tanks at the end of the day). They had been flying approximately 1.5 hours when the accident occurred. They were flying in a canyon and climbing towards a ridge. The pilot was moving the throttle in and out, and the engine sputtered shortly before the first tree strike. He was able to extricate himself from the wreckage and hiked out to seek help. The following is based on a conversation with the passenger in the left rear seat and an FAA inspector and a Cessna Aircraft investigator: The purpose of the flight was to look for elk in the Maple Mountain and Teat Mountain areas. They took off between 0540 and 0545, and had been flying for about 1 to 1.25 hours when the accident occurred. They were flying "even with some mountain tops" at about 7,800 feet when they entered a canyon in a south-to-north direction. They were at an altitude between 200 and 500 feet agl, and the pilot said they needed to get some altitude. The passenger said he realized they needed to "get out of there," and he said something to that effect to the pilot. He said the pilot was manipulating the throttle and the engine sounded like it was "bogging down." Then the pilot was holding the control yoke with both hands and looking out both sides of the airplane as if he might be considering a course change. It appeared as if the pilot was trying to climb over an approaching peak. They could not climb faster than the rising terrain. The airplane pitched up, struck some small trees in a nose-high attitude, spun around, and then hit the ground. He was unconscious for about a minute. When he regained consciousness, the right front and right rear passengers had already extricated the pilot. The following is based on a conversation with the passenger in the right rear seat and an FAA inspector: They took off approximately 0530 and flew up the Spanish Fork Canyon. The ground appeared to be rising faster than the airplane was climbing. The airplane struck some small trees with its "belly and tail," but continued forward until it struck a large tree with its right wing. The impact spun the airplane around. The on-scene investigation by both FAA and Cessna Aircraft personnel revealed no anomalies with the airplane. On August 31, 2004, the engine was functionally tested under the auspices of the Federal Aviation Administration. The engine operated satisfactorily and a maximum of 2,350 rpm was attained.