A Patterson girl broke her left arm in several places Thursday evening after she bounced off her bed and out a second-story bedroom window, officials said.
The girl, who is believed to be 6 or 7 years old, was airlifted to the University of California Medical Center in Sacramento.
Stanislaus County sheriff's Detective David Hickman said he believes that was done as a precaution and to ensure she did not have internal injuries.
He said the accident happened about 7:30 p.m. at a single-family home in the 1400 block of Wood Creek Drive.
Hickman said the girl was bouncing on the bed, which was less than a foot from the open window, went through the window screen, fell about 20 feet, and landed in dirt in the back yard.
Hickman said the dirt appeared to have been recently rototilled, which may have helped break the girl's fall.
Hickman said when he and deputy Matthew Wagner arrived, the girl already had walked into the house and was with her mother.
"She was talking and crying," he said. "This appears to have been a total accident."
Firefighters and EMS workers also responded.