An injured young woman is recovering after spending 12 days alone in the central Alberta wilderness, surviving on river water and berries, after fleeing from an alleged sexual assault.

The incident happened near the O'Chiese First Nation, near Rocky Mountain House.

The 25-year-old woman went missing on July 14, at the north end of the reserve.

She had been with a group of people driving on a dirt road when the vehicle broke down, said RCMP Cpl. Nick Munro. The occupants of the vehicle started walking home and the woman found herself alone on the road with a man she barely knew, he said.

That's when she was allegedly attacked by the man.

"She fled into the bush as a result of the altercation and became lost," he said. "She did get quite a severe blow to the head. She got lost and was just kind of wandering, trying to find her way out."

She survived on berries and river water, said Munro.

Man charged with assault

After her mother reported she was missing, police started searching for her with the help of local residents, search and rescue crews and a helicopter.

An oilfield worker found her walking along a road, 12 days after she had gone missing, about 10 kilometres from the place the vehicle broke down.

She remains in hospital with a broken jaw and infected cuts, said Munro.

"She was suffering from exposure, may have been mildly concussed from the altercation — not in great shape," he said Tuesday.

Despite her injured jaw, and through garbled speech, she was able to briefly talk about the ordeal with investigators, and to identify her alleged attacker.

A 36-year-old man is charged with sexual assault, aggravated assault and obstructing a peace officer.

He is set to appear in Rocky Mountain House provincial court on July 31.