The helicopter pilot reported that while enroute to the ski resort to pick up a patient, he decided to conduct an eastbound reconnaissance over the landing site and, after he saw the ground personnel, while scanning for obstacles, he spotted two cables in front and below the aircraft's flight path and initiated a go-around. He added power to clear the cables, and once the tail cleared the cables, he lowered the collective due to a slight droop in the main rotor speed. As he continued with the go-around, he initiated a 180º left turn to attempt an approach into the landing site. During the westward approach, about 20 feet above the ground, the main rotor speed decayed when he raised the collective to reduce his descent rate. He felt that due to his "faster than normal" decent rate, he would not be able to cushion the landing. Prior to touchdown, a medical crew member spotted an elevated steel barrier cable below and the pilot applied another 90º turn to the left to avoid a tail rotor strike. The helicopter touched down hard, bounced, rotated about 180º counterclockwise over the barrier cable, slid down an embankment, and came to rest upright. The helicopter sustained substantial damage to the fuselage and vertical stabilizer. The Director of Operations reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. The pilot further reported that during his preflight preparation, he did not calculate the hover in ground effect value (HIGE), the hover out of ground effect value (HOGE), or the density altitude for the designated landing site. He added that the accident flight was his second flight in a high altitude, mountainous environment and that most of his flight hours were accumulated at sea level in Texas. He was also not aware that there was an approach, landing and takeoff procedure provided by the ski resort. The director of operations added that the company was not aware that there were dedicated procedures for helicopter medical evacuation. The crew members added that the crew resource management skills and procedures were lacking, prior to and during the accident. They reported that there was no destination or helicopter performance briefing included with the helicopter preflight. The pilot added that he should have completed the go-around and circled back around to land. The Federal Aviation Administration inspector reported, during the time of the accident, the density altitude for the landing site at 9,793 ft was over 12,000 ft. The automated weather observation station located on an airport about 14 NM away, reported that, about the time of the accident, the wind was from 220° at 9 knots, gusting 17 knots. The pilot reported the wind was variable, about 5 knots. The helicopter was landing to the west.