On July 26, 2002, at approximately 1235 mountain daylight time, a Cessna 172S, CGKRA, was substantially damaged during an in flight collision with terrain at the end of a box canyon near Georgetown, Colorado. The commercial pilot and his passenger received minor injures. Aviation International (Canada) Inc. was operating the airplane under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the personal cross-country flight which had originated from Broomfield, Colorado, approximately 30 minutes before the accident. The pilot had filed a VFR flight plan with Grand Junction, Colorado. as his destination. The pilot said he departed Broomfield, Colorado, and planned to follow Interstate 70 to Grand Junction, Colorado. He said his cruise altitude was 10,500 feet, or "until higher was necessary." He said he was navigating with a WAC chart (World Aeronautical Chart; a visual flight rules [1:1,000,000] navigation chart). The pilot said, "after approximately 30 minutes of flight, I became aware of the narrowing of the valley and the significant rising ground elevation." When Eisenhower Tunnel (11,000 feet) became visible, he "realized more altitude was required, but full throttle could only produce minimal positive climb." The pilot said he considered a 180 degree turn, but was concerned about stalling in such a tight turn. He "decided to try climbing through a cleared ski run, just left off I-70," but subsequently impacted rising terrain at 11,500 feet (14,992 feet density altitude). Both wings sustained rib and spar damage, the cabin overhead was bent, and the engine firewall was crushed. The airplane's Pilot's Operating Handbook states that the service ceiling for this airplane was 14,000 feet. The service ceiling limit for a single engine airplane is the highest altitude at which a aircraft can maintain a steady rate of climb of 100 feet per minute.