The 73-year old driver was heading away from the Cheyenne Mountain Resort in Colorado Springs when she accidentally hit the accelerator instead of the brake.
She hit a car, which propelled her fast up a hill. Her vehicle went airborne in the process, crashed through a fence and landed in the pool.
Police estimate she was travelling at up to 60mph – but fortunately the pool was closed at the time.
Corey Youso, who was one of three bystanders who jumped in to get the driver out, said: “I jumped in through the window. She was stuck. She couldn’t get her seatbelt undone. So I unbuckled her seat belt and tried to coax her over to my side.
“Another gentleman had opened up the back door – at that time the vehicle just started to flood. I grabbed her and dragged her out the window. Got her out of the pool.
“But in an instant the car was submerged and under water – so by the grace of God everyone was okay. The pool wasn’t open, everything turned out for the circumstances well.”
The driver was not seriously hurt but was taken to hospital as a precaution.
She has since been released and police say she will be cited for careless driving.
Officers say they will have to drain the pool to get the car out, which may take more than a day.