On February 20, 2009, about 1200 Pacific standard time, a Cessna 172N, N6443E, collided with terrain while maneuvering in mountainous terrain near Big Bear Lake, California. The private pilot and the passenger received minor injuries. The airplane, which was registered to a private individual and operated by the pilot, sustained substantial damage. Visual meteorological conditions prevailed for the personal cross-country flight conducted under Title 14 Code of Federal Regulations Part 91, and no flight plan was filed. The flight originated from the San Bernardino International Airport, San Bernardino, California, at 1115, with an intended destination of the Big Bear City Airport, Big Bear, California. The pilot reported that during the preflight inspection, he drained a total of about 18 ounces of water from the wing fuel tanks. He then added fuel to each wing tank, rocked the wings by hand, drained the tanks and fuel strainer again, and found no water. Following departure, he climbed to about 6,000 feet mean sea level (msl) and conducted a series of practice flight maneuvers for his commercial pilot's license. After completing the maneuvers, the pilot departed the practice area to the northeast towards Big Bear City Airport. The pilot's route of flight to the airport took the airplane over mountainous terrain with elevations above 8,000 feet. He planned to fly up a ravine, and over the dam at the west end of Big Bear Lake. As the airplane entered the ravine he "put the plane in a climbing attitude, although the indicated airspeed lowered – the altitude remained the same." As the pilot flew further into the ravine he "was forced to lower [the airplane's] nose to maintain best angle of climb speed. As I lowered [the] nose I began to lose altitude." The pilot applied carburetor heat as he thought the engine might be experiencing carburetor icing. After observing a slight decrease in engine rpm, the pilot realized carburetor ice was not an issue and turned off the carburetor heat. The pilot then observed an area where he thought he "would have sufficient room to turn around" and initiated a left turn. However, as the "indicated airspeed was near 50 knots and [the airplane] was getting closer to the treetops," the pilot was "only able to complete 90 degrees of turn" before he "realized he was not going to make it." He "aimed for the area with the least amount of trees," and the airplane impacted terrain approximately 2 miles west of Big Bear Lake Dam at an elevation of about 6,100 feet. Review of photographs supplied by the airplane owner revealed that the leading edge of the right wing was buckled and crushed aft. The inboard portion of the left wing and flap exhibited severe deformation. The nearest weather reporting station to the accident site was located about 8 miles west of the accident site at Big Bear City Airport, elevation 6,752 feet. At 1210, this station was reporting wind 270 degrees at 5 knots; visibility 10 miles; skies clear; temperature 12 degrees Celsius (C); dew point -16 degrees C; and altimeter setting 30.20 inches of mercury. The calculated density altitude at the airport was 7,725 feet.