Tree saves woman, dog, from 20m fall in crash

A woman has been saved by a "lucky tree" after a car crash on Sydney's North Shore.

The woman was in the car with her dog when they crashed off the road and were halted short of a 20-metre plummet by the tree.

The driver was extracted through the rear of the vehicle in a delicate rescue operation.

The car had been left hanging over a steep precipice.

"She's extremely lucky," a NSW Fire and Rescue officer told 9NEWS.

"As one of the boys said, she's hit the lucky tree."

The driver is now being treated at Royal North Shore Hospital.

Her dog appeared to be uninjured.