Wilderness training may have played a role in the survival of two sisters who were found safe after spending 44 hours in California woods, police say.
Caroline (5) and Leia Carrico (8) were found on Sunday less than 3km from their home in Humboldt County, according to County Sheriff William Honsal.
They were found "safe and sound" on Sunday morning by a fire captain and firefighter who had followed the girls' boot tracks, Mr Honsal said.
"This is an absolute miracle," he said.
Although the girls were dehydrated and cold, they were uninjured and "in good spirits", Mr Honsal said.
He said the first responders provided them with fresh warm clothes and water.
He said the girls were trained in outdoor survival through their local 4-H club (youth organisation) and that authorities believed that helped them.
They also were wearing boots and had eaten granola bars at some point while they were missing, he said.
"To have a positive outcome like this is just absolutely amazing," Mr Honsal said.
Using helicopters and tracking dogs, dozens of police and rescue personnel combed a vast and rugged rural area in the frantic search for the sisters.
The girls had last been seen around 2.30pm on Friday outside their home in Benbow, a small community about 320 kilometres north-west of Sacramento.
The searchers included National Guard members from Fresno and the US Coast Guard, which provided one of its helicopters on top of a Black Hawk helicopter also being used.
Rescuers were hopeful about finding the girls on Saturday after they came across prints from the girls' rubber boots and wrappers from the granola bars, Lieutenant Mike Fridley said.
"The wrappers showed us a direction from where they started to where the wrappers ended up at," Mr Fridley added.
He said that he was the one who got to call the girls' mother to say that her daughters were alive.
"She melted on the phone, we had to hang up because she couldn't talk," he said.
Mr Honsal described the search area as vast, rugged and rural.
He said that the conditions were cold and sporadically rainy.