A 64-year-old woman from South Australia is missing near Kings Canyon in Central Australia, after what police describe as a "dispute" over the best way back to camp.
On Friday afternoon police intensified the search and deployed extra volunteers from Hermannsburg, an Aboriginal community about 131km south-west of Alice Springs.
The woman from the town of Millicent, about 400km south-east of Adelaide, went for a walk with her partner near the Salt Creek rest area yesterday morning, but the pair became separated in Watarrka National Park, about 240 kilometres from Alice Springs.
Overnight temperatures in Central Australia have been about 4 degrees Celsius and there are concerns the woman is only wearing light clothing.
Police said the woman and her partner, from South Australia, were camping at a rest area on the Luritja Road near Kings Canyon when they went for a walk yesterday.
Senior Sergeant Michael Potts said they had a squabble about the best route back to the camp site and separated and the woman has not been seen since.
"The information we received was there was a little bit of a dispute in relation to the actual way to get back to the rest area," he said.
"The husband went one way and the wife went the other.
"He returned about 15 minutes later to the rest area and she hasn't returned."
Senior Sergeant Potts said help came from a visiting interstate police officer.
"He also used his vehicle and sounded his horn for about two or three hours to see if we could attract her back towards the road, to the area," he said.
"She didn't come back after about two or three hours so we stood our guys down last night so they could be back first light this morning."
Superintendent Don Fry said the woman has been described as 180 centimetres tall and Caucasian, with a medium build, grey hair and blue eyes.
"She was wearing pink pants, a black-and-white check shirt, red jacket and a beanie.
"It is understood she did not have any water with her."