A 69-year-old woman who set off for a self-described "adventure before dementia" says she didn't expect it to become so literal after spending the night lost in the desert.

The Alice Springs resident of 50 years set out with friends on Sunday to explore Rainbow Valley Conservation Reserve — about 100km along sealed and unsealed road south-west of the town, far beyond the range of mobile phone reception.

The area has several short walks of about a kilometre in length, but police on Monday said they believed the group of three continued towards a nearby gorge.

When the woman, who wished only to be known as Rose, became tired about 1:00pm, she made plans to meet her friends at their vehicle at 3:00pm and began to journey back.

But at 3:00pm Rose was nowhere to be found and her friends notified police about an hour later.

Temperatures that day peaked at 34C, far less extreme conditions than those in which an American hiker perished on the nearby Larapinta Trail in January and two tourists died at Trephina Gorge about a year earlier.

But police on Monday said they still held concerns for Rose, who had not been located by nightfall.

In an interview with ABC Alice Springs' Alex Barwick, Rose recounted how good preparation and knowledge of survival skills saw her spend a relatively comfortable night in the desert.

The Rainbow Valley Conservation Reserve is about 100 kilometres south-west of Alice Springs. ( ABC Rural: Katrina Beavan )

A sleepless but well-prepared night

She said she became disoriented on her return to the vehicle.

"As soon as I got down and looked in the valley, I went to walk what would've been the right direction and I wasn't 100 per cent," she said.

"Even if I was 90 per cent [sure] I might've taken the chance, but it was 80 and I thought, 'No, be wise, sit down where you are, where you think you're supposed to be, and someone will come out'."

As night fell and nobody came across her, Rose said she initiated a survival plan, starting with gathering wood and lighting a fire.

"You've got to have a fire; it keeps animals away and it's a good signal for people to see smoke," she said.

It helped that the 69-year-old was also incredibly well-equipped, carrying four litres of water, enough food to last a day, matches, a phone with an inbuilt torch, a bandage, and two emergency blankets which kept her warm when temperatures fell to 17C.

"I made sure because you never know."

Throughout the sleepless night she said her main concern was that her friends might also have become lost.

Outback survival instructor Bob Cooper praised the Rose's efforts, saying the best advice was to sit down, light a fire and consider your options.

"You need to satisfy water, warmth, shelter, signals and food," Mr Cooper said.

The main risks to outback survival were dehydration and exposure to extreme temperatures, Mr Cooper said, adding that people should always notify others of their plans before setting out.

Drones deployed for first time

At first light on Tuesday police dispatched a search-and-rescue team alongside drones borrowed from the Australian Federal Police.

Senior Constable Tristan Waddell said he believed it was the first time the technology had been used for a search-and-rescue operation in Alice Springs.

He said the drones were useful for providing early sweeps of the area.

"Everything they do is GPS-tracked so the operators can set them on a search pattern," he said.

"They've got cameras on them and capability that they can even see footprints."

But it was a police helicopter conducting its third pass from Rose's last known location that sighted the reflective blanket she was waving.

By that time Rose had wandered a short distance from her camp and had wrapped her face in gauze to protect it from flies.

"They thought I'd hurt myself because I had elastic bandage and had some gauze with a bandage," she said.

Mr Waddell said Rose was found in good spirits, which Mr Cooper said was important in preventing emotional decision-making when people were lost.

"Once emotions stack up too high on that side of the brain, it will block off common sense and you won't be able to think rationally," he said.

Rose said it was the first and hopefully last time she would have to spend a night lost in the outback.

"I don't want it to happen again," she said.