On March 24, 2002, at 1500 mountain standard time, a Grumman AA-5 airplane, N9265L, was substantially damaged when it impacted terrain during an emergency descent/landing following an-flight encounter with weather near Lamar, Colorado. The airplane was registered to and operated by the pilot. The instrument-rated commercial pilot, and his one passenger, sustained minor injuries. Instrument meteorological conditions (IMC) prevailed, and an instrument flight rules (IFR) flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross-country flight originated from the Centennial Airport, Denver, Colorado, at 1230, and was destined for the Augusta Airport, Wichita, Kansas, with an intermediate fuel stop at the Garden City Regional Airport, Garden City, Kansas. According to the pilot, he contacted the Denver Automated Flight Service Station (DEN AFSS) and obtained a weather briefing for the flight to Garden City. The briefer informed the pilot of IFR conditions along the route of flight and an airmet for icing conditions in the northern 1/3 of the state of Colorado; however, the route of flight was not within the airmet's boundaries. The pilot then filed an IFR flight plan to Garden City. The flight departed and climbed to a cruising altitude of 9,000 feet. The pilot stated that the airplane was in IMC when he observed that the airplane's groundspeed was less than he expected, and the outside air temperature was slightly below freezing. He contacted air traffic control (ATC), requested a descent to 7,000 feet, and initiated a descent. The pilot stated that the flight was near Lamar when rime ice began to accumulate on the airplane's windshield, wings, and vertical stabilizer. The flight continued and was 25-30 miles past Lamar when the pilot advised ATC that the airplane could not maintain altitude due to icing. ATC recommended that the pilot reverse course and divert to the Lamar Municipal Airport (LAA) in Lamar. The pilot then turned back toward LAA. The pilot stated that the airplane remained in a shallow descent; however, he was able to maintain 80 mph airspeed. The flight broke out of the cloud layer at 4,500 feet, and with the assistance of a handheld GPS, the pilot proceeded direct to LAA. The pilot stated that his view was obstructed by the ice on the windshield. The entire windshield was covered with ice, except for a 6-inch radius semi-circle that was cleared by the airplane's windshield defroster. The flight continued toward Lamar; however, the flight encountered rising terrain. Subsequently, the airplane impacted the ground and traveled 100 feet before coming to a stop upright, approximately 1 mile southeast of LAA. During the impact, the firewall was wrinkled, the engine mount was damaged, and both wings sustained structural damage.