On April 28, 2004, at 1520 mountain daylight time, a Beech 95-C55, N282JL, was substantially damaged when it struck terrain during a precautionary landing at Garfield County Regional Airport (RIL), Rifle, Colorado. The private pilot and passenger were not injured. Visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The flight to Glenwood Springs, Colorado, originated at Telluride, Colorado, at approximately 1415. According to the pilot, while en route to Glenwood Springs, he experienced an electrical system malfunction. Due to the wind gust conditions at Glenwood Springs, he decided to divert to Rifle. While en route to Rifle, the airplane's electrical system became more erratic, which included the illumination of all warning lights on his digital exhaust gas temperature (EGT) gauge and the indication of "extreme" engine temperatures of over 1,650 degrees. Shortly thereafter, the electrical system failed. The pilot reported that he immediately attempted to lower the flaps and landing gear. The flaps partially lowered. The pilot was able to hand crank the landing gear half way down. However, because of the severe turbulence, the pilot asked the passenger to takeover cranking the gear down while he flew the airplane. When the passenger finished, the pilot verified that the landing gear crank had "quit turning." The pilot stated that, due to the "extreme danger" of a possible engine fire, he elected not to attempt a fly-by to verify that the landing gear was extended. When he attempted to land on runway 26, he felt both propellers strike the runway. When he "cut" the power to both engines, the airplane settled onto the runway, and slid approximately 1,000 feet before coming to a stop on the grass just off the right side of the runway. The pilot realized that the passenger had inadvertently raised the landing gear, resulting in an unintentional gear-retracted landing. Later, it was determined that several fractured propeller pieces had impacted the fuselage resulting in substantial damage to several fuselage bulkheads. An examination of the airplane's electrical system, which included a 2-hour ferry flight, showed no anomalies.