The four-time overall World Cup champion lost balance on her right leg while landing after a jump. Her ski came off immediately, and Vonn slid off course and hit a gate before coming to a halt.
She received treatment on the slope for 12 minutes before going to the hospital. Her U.S. team had no immediate information on her condition.
The crash came almost exactly one year before the start of the 2014 Winter Olympics in Sochi, Russia.
Vonn returned to the circuit last month after an almost monthlong break from racing to fully recover from an intestinal illness that put her in a hospital for two days in November.
Vonn trailed race winner Tina Maze of Slovenia by 0.12 seconds shortly before the crash.
The race, which was postponed for 3½ hours because of fog, resumed after another 15-minute delay. Several racers struggled with the conditions.
"It's not a very difficult course, but in some parts you couldn't see anything," Fabienne Suter of Switzerland said.
