On February 19, 1995, at 1915 central standard time, a Cessna 177B, N34958, was substantially damaged during landing near Terlingua, Texas. The commercial pilot and private pilot rated passenger were not injured. Visual meteorological conditions prevailed for the Civil Air Patrol public use flight from Presidio, Texas. The pilot, who was occupying the right seat, reported that "it was getting dark" as he approached the unlighted Terlingua Ranch Airport. Both the pilot and his passenger stated that the runway was visible on final approach. The pilot reported that he "lost the centerline drifting to the right" during the landing to runway 20. The airplane exited the right side of the runway, impacted brush, and continued to travel forward until it encountered a ravine where it came to rest. The operator reported that the right main gear and nose gear separated from the airplane. The fuselage was buckled aft of the baggage compartment and the right wing spar was damaged.