A woman lost in an Arizona forest for nine days survived by drinking pond water, eating plants and spelling out "help" on the ground with sticks, authorities said.

The sign helped lead rescuers to Ann Rodgers, 72, in the White Mountains of eastern Arizona earlier this month, the state Department of Public Safety said.

Ms Rodgers told a Tucson TV station that she had food and water in her car, but ran out after several days and turned to survival mode.

"I was eating desert plants. My dog was too, diving into clovers and finding all the places that were the easiest to go," she told KOLD.

Ms Rodgers went missing March 31 as she headed to visit her grandchildren in Phoenix. She got lost, and her hybrid vehicle ran out of gas and electric power, authorities said.

Her car was discovered three days after a search began, but rescue crews struggled to find her.

Authorities came across her dog April 9, and a department flight crew spotted a "help" signal made of sticks and rocks on the ground.

Ms Rodgers had left the area, but she was found nearby on the Fort Apache Reservation after starting a signal fire.

The Department of Public Safety said Ms Rodgers was suffering from exposure, but she was in fair condition and able to walk to and board a helicopter with little assistance. She was taken by helicopter to a hospital in Payson for treatment and later released.