An RNAV Approach was conducted to Runway 34 and based on the groundspeed observed on the GPS, a tailwind estimated to 10 to 15 knots was encountered. In an attempt to touch down at the beginning of the 1899 foot long runway, the throttle was brought to idle too early and the aircraft touched down between 5 and 10 feet before the threshold. The right main gear struck a rock, which caused damage to the right gear leg. The aircraft touched down on the centerline and stopped about midway down the runway after a 180 degree turn. There were no injuries. This flight was the crew’s third trip of the day to this airport. For the first 2 trips, tailwind was also encountered during the final stage but with decreasing wind velocity on the ground. The windsock indicator light was NOTAM’d u/s. The ceiling was estimated at about 2000 feet with a visibility of about 5 to 7 miles. At the time of the occurrence, the CARS operator was off duty and the wind was reported to the crew by a First Air ground agent to be from the east at about 10 knots.