UHP troopers say the crash happened at mile post 337 at around 3:00 p.m.
One woman was flown by helicopter to a nearby hospital, while an 11-year-old girl was taken by ground.
Troopers say the girl was ejected from the vehicle, although all three people in the truck were wearing seat belts at the time of the crash.
UHP troopers say a man who was riding in the truck was not seriously injured.
Troopers were investigating the possibility of gusting winds mixed with vehicle speed as possible causes for the crash.