On August 18, 2001, at 1425 hours Pacific daylight time, an Aerospatiale AS 355F1 helicopter, N53LH, rolled onto its side and came to rest during takeoff at a remote location, 4 miles east of Vinton, California. The commercial certificated pilot, two flight nurses, and one patient were not injured. The helicopter was substantially damaged. The on-demand, air taxi, medical transport flight was operated under 14 CFR Part 135, by Rocky Mountain Holdings, LLC. Visual meteorological conditions prevailed and a company VFR flight plan was filed. The flight was destined for Reno, Nevada. According to the operator, the pilot reported that, during liftoff, he encountered a loss of visual reference due to a "brown out" condition at 3 feet above ground level. He attempted to land the helicopter without any visual reference; however, the right skid contacted the ground first. A rolling motion to the left was created and, after the left skid contacted the ground, a dynamic rollover ensued. The helicopter came to rest on its left side.