NEVADA CITY, Calif. (AP) — A California woman was found atop a river canyon this week near the Yuba River in Northern California 12 days after disappearing from a mining camp site.

The Nevada County Sheriff’s Office said Friday the 24-year-old Sacramento woman was severely dehydrated and emaciated when found. She was airlifted to a hospital for treatment. Officials said the extent of her injuries were unknown.

“The Sheriff’s Office and our search and rescue volunteers covered extensive ground throughout our search, and we are thankful today to find her alive,” Sgt. Dustin Moe, who found the woman, said in a statement.

Esmeralda Marie Pineda went missing in August when she was camping with friends in Nevada City, a town about 63 miles (101 kilometers) from Sacramento. Pineda had told her friends she wanted to go back to Sacramento before she disappeared the next morning, KYMA reported. Officials said Pineda must have climbed up the canyon walls before being rescued. They weren’t sure how Pineda survived nearly two weeks in the wilderness.

The sheriff’s office started searching for her the day she disappeared. Law enforcement and volunteers had to “repel into and out of the canyon” while facing “treacherous” canyon area, the sheriff’s office said.