On January 8, 2000, at 1443 mountain standard time, a Piper PA-23-250, N128Y, made a forced landing 10 miles southwest of Rock Springs, Wyoming, following a total loss of power. The private certificated, instrument rated pilot was not injured and the aircraft sustained substantial damage. The flight was operating under Title 14 CFR Part 91 and an instrument flight rules (IFR) flight plan had been filed in the air. Instrument meteorological conditions (IMC) prevailed for this cross-country flight from Rock Springs, to Boise, Idaho. The flight originated from Rock Springs at 1407 on a visual flight rules (VFR) flight plan. According to the pilot, he departed Rock Springs as snow was starting and proceeded southwest in order to stay in visual conditions. He contacted Salt Lake Air Route Traffic Control Center (ARTCC) and filed an IFR flight plan. He then proceeded on his flight in IMC conditions. The pilot said that after about 15 minutes of flight in IMC conditions, the right engine began to fail due to induction system icing. The loss of power to the right engine was followed by loss of power to the left engine and an emergency, landing gear retracted, landing was made by the pilot on rough uneven terrain. Recorded weather conditions at Rock Springs when the flight departed were 200 foot overcast skies, and 1/2 mile measured visibility with snow. The wind was from 280 degrees magnetic heading at 17 knots with gusts to 23 knots. The temperature was 25 degrees Fahrenheit (F.) and the dew point was 19 degrees F. The altimeter setting was 29.86 inches of mercury. Other than the pilot's report of IMC conditions, weather conditions at the accident site were not recorded.