State police in Fayette County say the vehicle veered off a dirt road in Connellsville Township at about 12:15 a.m. Sunday in Connellsville Township. They say two people were ejected when the vehicle landed.
Authorities said all four people had to be hoisted up the slope due to their injuries and the remote location.
Officials said three men and a woman were flown to Presbyterian Hospital with injuries said to be very serious.
The cause of the crash is under investigation.