The accident occurred Sunday at the Omni Bedford Springs Resort Christmas ceremony, The Altoona (Pa.) Mirror reported.
The driver, Ernie Alwine, suffered cuts to his face, and was airlifted to Conemaigh Memorial Medical Center in Johnstown.
Alwine's young daughter had minor injuries, Bowden said.
The horses became frightened, likely when a band began playing, Alwine fell under under the sleigh and its passengers -- actors dressed as Santa and Mrs. Claus -- jumped to safety, Bowden said.
"We're not 100 percent sure why, but the horses spooked," Bowden said. "Mr. and Mrs. Claus bailed out."