A second member of a trio who went missing during a drive in the Northern Territory outback a fortnight ago has been found alive.

A pastoralist found Phu Tran, 40, in the Palmer Valley on Tuesday morning, two weeks after he and his companions Tamra McBeath-Riley and Claire Hockridge were last seen.

Ms McBeath-Riley, 52, was rescued on Sunday after she was able to find water in the outback south of Alice Springs. Police say Mr Tran also found water. Ms Hockridge, 46, remains missing – along with Ms McBeath Riley's Staffordshire bull terrier, Raya.

Ms McBeath-Riley spent Sunday night in hospital, but was released on Monday afternoon. She said she was "worried to death" about her companions.

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Inset: Phu Tran was found on Tuesday morning – nearly a fortnight after going missing.

The trio tried for three days to free their ute after it became bogged, Ms McBeath-Riley said.

"We tried many times to try and get out, but just couldn't get out, so ventured forth to try and find some shelter and some water," she said.

"During the day it's just really hot, so we dug ourselves under the car during the day into the sand."

After leaving their vehicle where it became bogged in the bed of the Finke River on November 19, she said the three drank from a cattle watering hole and ate biscuits and beef noodles before splitting up.

Ms McBeath-Riley said Ms Hockridge and Mr Tran had intended to head towards the Stuart Highway, about 22 kilometres from where they separated.

When she was rescued, she thought the pair – who had a GPS and compass with them – would have earlier reached the highway.

Earlier on Monday, police said they had found a set of footprints they hoped would lead to the missing duo.

Alice Springs Superintendent Pauline Vicary said the trio had left a note inside their vehicle to indicate the direction they were heading.

They then walked about 1.5 kilometres west, where they found puddles of ground water from unseasonal showers that had fallen over the dry river system in the past fortnight.

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Inset: Tamra McBeath-Riley said she was worried to death about her two missing friends.

For one desperate week they stayed together, gathering the dirty water, boiling it when they could and using a shirt to strain out the sediment, Superintendent Vicary said

She said the terrain in the area was diverse.

"There's sandy dunes, there's hard clay, there's areas of dense trees, but there are also rocks and rangers in the area," she said.

Ms McBeath-Riley suffered from dehydration, exposure to poor quality water and temperatures that nudged 40 degrees in recent days.

She was rescued after a local station worker noticed tyre tracks and alerted police to an area that was not previously searched.

Authorities found the ute and from there tracked to the group to the Finke River site where they found water. They found Ms McBeath-Riley there.

-with AAP