On March 16, 2003, at 2245 mountain standard time, an Embraer EMB-120ER, N214SW, operating as SkyWest Airlines Flight 3622, and piloted by an airline transport pilot, sustained minor damage during takeoff roll, when the airplane departed the left side of runway 20 (7,802 feet by 150 feet, slush/snow-covered, asphalt) at the Cedar City Municipal Airport (CDC), Cedar City, Utah, and struck a runway remaining marker before coming to a stop. Night instrument meteorological conditions prevailed at the time of the incident. The scheduled, domestic, passenger service flight was being conducted on an instrument flight rules flight plan from CDC to St. George, Utah, under the provisions of Title 14 CFR Part 121. The captain, first officer, flight attendant, and 12 passengers reported no injuries. The flight was originating at the time of the incident. The captain reported they were due to takeoff at 2136. The airplane was delayed approximately 17-18 minutes at the end of the runway awaiting clearance. During that time, approximately 1/4-inch of snow had accumulated on the airplane. The captain reported they went back to the ramp area to be de-iced. While being de-iced, the captain reported they coordinated with air traffic control to expedite their departure. The captain reported they taxied from the ramp to the runway and began the takeoff roll. The captain said that everything was fine initially. When they passed the 7,000 foot remaining marker, the airplane began tracking left. The captain said he tried to correct the situation with rudder and differential power, but the airplane continued to track left. The captain said, "I lost control of the situation when the left mains got into the soft earth at the edge of the runway." The first officer reported that just after they had advanced the power levels forward, the Ice Condition light illuminated. The first officer notified the captain and noticed that the airplane was pulling to the left. The first officer said the captain was attempting to correct the condition when the airplane pulled hard left. The airplane was straddling the runway lights. The first officer said the captain then aborted the takeoff. The first officer said that with braking, they slid off the runway and slowly spun to the left leaving the airplane facing east when it stopped. The airport manager reported that at the time of the incident, the runway was covered with 1 to 1-1/2 inches of snow. He said the bottom 1/4 inch of the snow was slush. The airport manager said he verified the runway lights were on and bright and the signs were lit. The airport manager said he examined the tire tracks in the snow and reported the airplane began its takeoff roll to the left of the runway centerline. The airport manager reported the tire tracks proceeded further left of centerline as they proceeded down the runway until they were off the left side of the runway. The airplane came to a stop just off of the left side of runway 20, approximately 2,400 feet down. An examination of the airplane showed that both propellers' blades were torsionally bent and curled at the tips. The rotating beacon on the bottom of the airplane's fuselage was broken aft. Fuselage skin in the vicinity of the beacon was torn and wrinkled. There were also several punctures in the lower fuselage skin. An examination of the airplane's systems revealed no anomalies. The reported weather at CDC at the time of the incident was ceilings 400 feet broken, 1,100 feet overcast, visibility 1/2 mile, snow and fog, temperature and dew point 32 degrees Fahrenheit, and an altimeter setting of 29.59 inches of Mercury.