On September 13, 1996, about 1155 Alaska daylight time, a Bell 206B helicopter, N7982J, collided with mountainous terrain about 35 miles west of Cantwell, Alaska. The helicopter was being operated as a visual flight rules (VFR) cross-country on demand passenger flight to Teklanika Lake, Alaska, under Title 14 CFR Part 135 when the accident occurred. The helicopter, operated by ERA Aviation Inc., Anchorage, Alaska, was destroyed. The certificated commercial pilot received minor injuries. One passenger was not injured. A second passenger received serious injuries. Instrument meteorological conditions prevailed in the area of the accident. VFR company flight following procedures were in effect. The flight originated from the area of Colorado, Alaska, about 1125. The operator reported that the pilot made several inquiries about the weather conditions along the route of flight for the intended destination on the north side of the Alaska Mountain Range. The pilot telephoned the ERA company office in McKinely Park, Alaska, and received a report of snow showers and 1/2 mile visibility. Ridge tops in the area were visible after the snow showers moved through the area. The pilot conferred with his passengers and agreed to "take a look". The flight departed Anchorage, Alaska, about 0915 with a special VFR clearance and proceeded northbound. The pilot observed low ceilings and snow in the area of Windy Pass, 6 miles north of Cantwell, and about 1105, landed at a helipad known as the Igloo, located on the highway about 16 miles south of Cantwell. The pilot again contacted the ERA office in McKinely Park and was informed the weather was "still down". At 1125, the pilot decided to proceed up the Colorado Creek drainage in a westerly direction to cross the mountain range at Anderson Pass, located about 23 miles west of the Igloo. The pilot encountered low ceilings, including fog and snow in the pass and began a turn to reverse direction. The helicopter collided with snow covered terrain at 5,300 feet mean sea level. The operator indicated the pilot encountered low ceilings, including fog and snow in Anderson pass. He lost visual contact with the terrain and encountered whiteout conditions. The pilot began a turn to reverse direction and became disoriented. The helicopter collided with snow covered terrain at 5,300 feet mean sea level. The pilot obtained a weather briefing from the Kenai, Alaska, Automated Flight Service Station (AFSS) at 0840. The flight service station specialist provided the pilot with weather information from Talkeetna, Wasilla, Cantwell, Chulitna, McKinley National Park, and Healy, Alaska. The flight service station specialist indicated Talkeetna was experiencing instrument flight rule conditions (IFR) with a visibility of 3/4 mile in light rain and mist. Wasilla was reporting 1/2 mile visibility and an indefinite ceiling of 500 feet obscured. Cantwell and Chulitna were reporting 10 miles visibility. The automated weather observation system (AWOS) at McKinely Park was reporting the visibility of 10 miles, scattered clouds at 2,400 feet and broken clouds at 4,100 feet. Healy was reporting 10 miles visibility, broken clouds at 1,000 feet and overcast conditions at 4,000 feet. The pass between McKinely Park and Healy (Windy) was estimated to be closed due to fog all quadrants and lower visibility toward the south. The flight service station specialist and the pilot then had a discussion about the differences between the McKinely Park AWOS observation and the ERA company office's report of the weather conditions. The specialist provided the area forecast that included marginal VFR to IFR conditions throughout the day. The forecast reported marginal VFR due to ceilings and rain, temporary IFR due to ceilings and snow in Windy Pass. The specialist indicated that VFR was not recommended and included a meteorological advisory to airmen (AIRMET) for IFR conditions in the Cook inlet and Susitna Valley. He also included an AIRMET for isolated moderate turbulence below 6,000 feet.