On February 24, 1997, at 1315 hours Pacific standard time, a Bell 206B helicopter, N42SS, collided with high vegetation while landing on a remote helipad on Mount Potosi, about 4 miles south of Mountain Springs, Nevada. The helicopter was destroyed by postimpact fire. The airline transport pilot and one passenger received minor injuries, and one passenger received serious injuries. The helicopter was operated by Sundance Helicopters, Inc., Las Vegas, Nevada, as an on-demand nonscheduled domestic passenger flight under 14 CFR Part 135 when the accident occurred. The flight originated in Las Vegas at 1240. Visual meteorological conditions prevailed at the time and a company VFR flight plan was filed. The pilot indicated he encountered an updraft on short final approach to the mountain helipad, which resulted in aborting the first two approaches. On the third approach, the pilot encountered updrafts again and attempted to maneuver the helicopter by turning downslope and avoid the upsloping terrain. While in the turn, the pilot encountered a downdraft and the helicopter struck high vegetation and the ground. The helicopter rolled downslope and caught fire after it came to rest. The occupants were able to egress the helicopter before receiving any burn injuries. The pilot reported that he checked weather by listening to the Reno Flight Service Station recorded weather. SIGMENT Yankee was in effect and was forecasting severe turbulence below 15,000 feet msl in the area due to a steady northeasterly flow. The SIGMENT stated, "Strong updrafts and down drafts over mountains and also low level wind shear expected." Mount Potosi, elevation 8,514 feet msl, is located about 20 miles west of Las Vegas. The Las Vegas scheduled record observation at 1256 hours was reporting winds from 020 degrees at 19 knots.