Steamboat Springs Lance Armstrong, the 1999 Tour de France champion, has apparently had enough of mountain biking for the time being.
Armstrong dropped out near the halfway point in the 26.5-mile Rabbit Ears cross-country race Thursday in the Mercury Tour, and left Steamboat Springs for Vail shortly thereafter.
He won't compete in subsequent stages of the race which continues through Sunday.
Armstrong's agent issued a statement saying Armstrong fell a couple of times in the early portion of the race on Thursday, bruised his left knee and felt fatigued, so he dropped out. Armstrong's progress in the race was difficult to monitor as the cross-country race left Rabbit Ears Pass and headed into backcountry single-track trails on its route up the backside of the Steamboat Ski Area.
However, eventual winner Jerome Chiotti said he saw Armstrong fall. The two men had sprinted away from the pack on a four-wheel drive road early in the race.
But Armstrong's difficulty apparently began when the course changed to single track.
"There were some rocks, and he went over the bars," Chiotti said.
After the first crash, Armstrong overtook Chiotti once more, only to crash again.
Armstrong's teammate, Travis Brown, said the road racer had mud all over his back and was eight minutes behind the leaders when he finally dropped out.
Armstrong said Wednesday the crush of media attention since he won the Tour de France earlier this summer has disrupted his training.