Beisker RCMP and STARS were called to an ATV rollover southwest of Linden at around 4:15 p.m. Sunday.
Two children and a 14-year-old girl were riding the quad when it flipped over.
The girl was driving the off-road vehicle and was airlifted by STARS to a Calgary hospital, the two other children suffered minor injuries.
All of the children were not wearing helmets.
An investigation into the incident is still on going.