On December 17, 2002, about 2158 Pacific standard time, a Eurocopter Deutschland EC-135 P1 helicopter, N311MS, sustained substantial damage subsequent to a hard, off-airport landing two miles north of Loon Lake, Washington. The helicopter is owned by INHS Leasing Company, LLC, Spokane, Washington, and was being operated by Metro Aviation, Shreveport, Louisiana, as a visual flight rules (VFR) EMS flight under the provisions of Title 14, CFR Part 135. The airline transport pilot-in-command, the two EMS crewmembers and patient being transported, were not injured in the accident. The flight originated from Mt. Carmel Hospital, Colville, Washington, approximately 15 minutes prior to the accident. The pilot's planned destination was Sacred Heart Medical Center, Spokane, Washington. In a written statement dated December 19, 2002, the pilot reported that when he departed Colville, the weather was mostly clear with a visibility of more than 10 miles. He stated that as the helicopter approached the area around Loon Lake (approximately 30 miles southeast of Colville) they encountered heavy snow showers. The pilot further stated that, "While attempting to slow the helicopter and either turn around or make a precautionary landing on a road (Hwy 395) the helicopter entered a high rate of descent. I ended up making a hard landing on Hwy 395 in pretty much a complete white out." The 2153 weather observation (ASOS) at Deer Park, Washington, 10 miles southeast of the accident site, reported a visibility of 4 statute miles and light snow; scattered clouds at 2,800; broken clouds at 3,700; overcast skies at 4,600; temperature minus 1 degrees Celsius and dew point minus 1 degree Celsius. The aviation area forecast (FA) issued at 1945 PST on December 17, valid during the accident time frame, reported widely scattered snow showers East of the Cascades, to include Northeastern Washington. The pilot reported that he obtained a weather briefing via the Data Transmission Network (DTN) prior to the flight from Spokane.