The aircraft sustained substantial damage during a wheels-up landing at approximately 1410 Mountain time. The solo Airline Transport pilot sustained minor injuries; instrument conditions prevailed. The pilot was cleared for an ILS approach to Runway 34 but went missed approach for no gear indication. The pilot subsequently performed a wheels-up landing. During the landing, the airplanes right wing struck a runway sign. A witness that recovered the airplane following the accident reported that the airframe was covered with ice that measured approximately -inch thick. Weather was reported as ceilings 400 broken, 5500 broken, 7500 overcast, 1 mile visibility, temperature 1 degree Fahrenheit (F), dew point -2 degrees F and winds from 040 degrees at 16 knots.