Backpacker found after 12 days missing in Australian bush

German backpacker Carolina Wilga has been found alive but "ravaged by mosquitoes" 12 days after going missing in remote bushland in Western Australia, police said.

A member of the public found the 26-year-old on a bush track, and she has been taken to hospital in Perth for treatment, police said.

"She's been ravaged by mosquitoes. She's obviously been through an amazing journey, a trauma, and no doubt will be a testimony demonstrating her bravery in the circumstances out there," WA police inspector Martin Glynn told reporters.

"I think once we do hear her story, it will be a remarkable story."

Ms Wilga had been last seen on 29 June arriving in a Mitsubishi van at a general store in the small agricultural community of Beacon, northeast of Perth.

Police found the van yesterday, apparently abandoned after getting stuck in dense bushland about a two-hour drive from where she was last seen, sparking a major land and air search of the area.

"She's obviously coped in some amazing conditions. There's a very hostile environment out there, both from flora and fauna. It's a really, really challenging environment to cope in," Mr Glynn said.

No serious injuries

"The weather conditions have been really adverse, with temperatures getting down to zero. Night has been rain. There's been reports of all sorts of challenges in that terrain."

Her van was found with plastic orange traction tracks placed beneath the rear wheels, apparently after getting stuck in the terrain.

It was unclear how far she had strayed from the vehicle.

"Obviously, she would have covered a lot of ground in that time as she tried to make her way out of there," Mr Glynn said.

"She doesn't appear to have any serious injuries. She obviously has a lot of significant minor injuries. She has obviously a need for medical attention, so she's injured, and obviously, hopefully, once she recovers, a better assessment can be made."

Ms Wilga's family has been notified, he said.

"It's a really good outcome."

Police say she had spent two years backpacking around the country and was working at mine sites in Western Australia.