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In 1984 a group of Australian Aboriginal people living a traditional nomadic life were encountered in the heart of the Gibson desert in Western Australia. They had been unaware of the arrival of Europeans on the continent, let alone cars - or even clothes.

If you want to know how Australian Aboriginal peoples lived for 40,000 years, just ask Yukultji. She stepped into the 20th Century just 30 years ago. She is the youngest member of the Pintupi Nine, the last family of nomads to roam the territory around Lake Mackay, a vast glistening salt lake spanning 3,500 sq km (1,350 sq miles) between the Gibson and Great Sandy deserts of Western Australia.

"When I was young I would play on the sand dune and when we saw the old people returning to camp we would go back and see what food they had brought with them. After we ate we'd go to sleep. No blanket, we would sleep on the ground," says Yukultji.

"Then we would go to another waterhole and make another camp."

Before 1984, the Pintupi Nine lived just as their ancestors had done. Waterholes in this area are often 40km (25 miles) apart or more, and every day was spent walking in the relentless heat from one to another. "Sometimes there was no water, so we would hunt for goanna," says Yukultji. The blood of these monitor lizards provided vital moisture when a water soak was dry.

Image copyright Safia Desai Image caption The three sisters Yukultji, Takariya and Yalti

The discovery of the group caused a media sensation, but headlines referring to the "lost tribe" annoyed them - they weren't lost, they insist, just separated from their relatives, and other members of the Pintupi clan.

The Nine consisted of two sisters and their seven teenage children - four brothers and three sisters, who shared one father. So how had they become so isolated?

In the 1950s the British began conducting Blue Streak Missile tests over the Western Desert region, and the Australian government decided to "round up" the desert nomads and move them into settlements. All of the Pintupi were taken away apart from this one family, which was overlooked. From then on, suddenly alone in the desert, they saw very few signs of anyone else's existence.

Yukultji remembers seeing aircraft when she was very young. "The plane would fly over and we would hide in the tree. We would see the wings of the plane and we would get frightened. We thought it was the devil and so we kept hiding under the tree. When the plane had passed we would climb down from the tree."

Her older sister, Takariya, remembers coming across a plane that had crashed. "We found some rope in it and we tied it around our waist. We didn't know it was rope. We would tie it around our waist so that we could hang our goannas from it," she says.

Their father may have been aware of the settlements - the children remember him describing what must have been a sheep, but when they asked to be taken to see such a strange thing, he refused.

In the 60s and 70s Aboriginal people were allowed to move back to their land, but Kiwirrkurra community, where the Pintupi live, was only built in 1984, when a borehole was sunk there for the first time. It is the most remote community in Australia - a two-day, 700km (440-mile) drive from Alice Springs along a bright red sand track lined by Spinifex grasses, with an occasional cluster of Mulga trees.

Image copyright ALAna Mahony

Image copyright Alana Mahony Image caption Kiwirrkurra country

The creation of the settlement brought the Pintupi closer again to the family that had remained alone for up to 20 years. Those most closely related to the Pintupi Nine had often spoken about family members who were still "in the bush" and had not been accounted for - they had always wondered what had happened to them.

Warlimpirrnga, the eldest brother, and the head of the family after his father's death, remembers the day that the family stumbled across other members of the clan.

I tasted the sugar and it tasted so sweet - like the Kulun Kulun flower Warlimpirrnga

"We had just speared a kangaroo. We could smell the faeces of other humans in the air" - they were probably a couple of kilometres away - "and we saw smoke in the distance.

"We moved closer and stood on a rock and could see people camping down below. So I began to move closer to their camp. I ran towards where they were standing. Then I snuck over closer. I coughed. The people heard me. It looked like they were scared. They became frantic, running back and forth," he says.

"This is my grandfather's land," Warlimpirrnga said. One of the men started filling a billycan with water for them. "When he did, we thought, we won't spear him," says Warlimpirrnga. "They were so scared. They were really scared of us, scared out of their wits."

The campers were a Pintupi man, Pinta Pinta, and his son, Matthew, who had decided to set up an outstation at a place named Winbargo, 45km from Kiwirrkurra. The young man panicked and fired a shotgun in the air - all parties scattered, and the two men drove off at speed, despite a flat tyre.

"We heard the sound of that car long into the distance," says Warlimpirrnga.

This was the first time he and his brother Thomas had experienced running water, clothed people or a motor car.

Pinta Pinta and Matthew raced back to to tell the others what they had seen. We know their side of the story from the diaries of Charlie McMahon, now a well-known musician but back then the only "whitefella" helping 60 to 80 Pintupi to establish the community at Kiwirrkurra. They called him Murrahook, because he had a hook for an arm.

Media playback is unsupported on your device Media caption Charlie McMahon’s 8mm film shows daily life in Kiwirrkurra in 1984

"Saturday, 13 October: Pinta Pinta and many others come to my camp late at night very excited; they relay the story of meeting two naked men," McMahon wrote. "They said one of the men, the tall one, came towards him at the hand pump, laying his spears on the ground as he approached and asked Pinta Pinta for water. Pinta Pinta worked the hand lever pump to fill up a billycan. Then his son Matthew fired a shotgun, blasted into the air. Pinta Pinta and his son were startled by the two naked, wild-men with spears... they thought they were kaditcha or evil spirits."

By the following day, the community had calmed down sufficiently to realise the men were probably long-lost relatives. McMahon records the moment they decide to track them down. "A decision to go out on Monday to find them and 'give them trousers' is made."

A three-day chase through the bush followed. One of the members of the search party, Joseph Tjapaltjarri, was sure he recognised the footprints they were tracking - he remembered the shape of the foot from his childhood and knew it belonged to his "skin-brother", Warlimpirrnga.

Image copyright ALAna Mahony Image caption Warlimpirrnga (left) with Joseph, who recognised his footsteps

McMahon was back at base camp, waiting for news. "Tomorrow we will find the two men's tracks and maybe, tonight, the last of the ancient people will spend their last night free of the modern world. However, I'm quite prepared to turn back and won't feel in any way daunted, if they stay out here as they are," he wrote in his diary.

Yukultji, a young teenager at the time, was the first to be found, together with her sister Yalti - she says it was a frightening and bewildering experience. "We had nowhere to go. My mother hid in the Spinifex. The men grab us and put us in the car, leaving Takariya's mother behind, they didn't see her in the bushes. The men took off their shirts and gave it to us."

Yalti says her senses where overwhelmed by the experience of travelling in a car for the first time. "We were frightened and we covered our faces. As the car kept moving, we looked up and the trees and Spinifex were moving around us and we kept hiding. When the car stopped I jumped off all frightened and dizzy, my head moving. It was the first time I had been in a car. I didn't know what was happening."

Warlimpirrnga tracked the car and there was a confrontation - he was the leader of the Pintupi Nine and a man of strength and determination. Armed with a spear, he was preparing to defend his family, but as he took aim his mother yelled out: "Stop that, that's your brother, your mate, leave him, that's your brother."

At this point Joseph Tjapaltjarri and Freddy West explained who they were, and the fear and tension evaporated. Warlimpirrnga could see that the men were not hurting the women and he slowly began to identify the relatives standing in front of him.

The Pintupi Nine's experience of first contact was less traumatic than it could have been. Unlike the Pintupi who had been rounded up 30 years earlier, they were met by relatives who spoke the same language, and it was a whole day before they met a white man.

Image copyright News ltd/newspix/rex Image caption The Pintupi Nine in 1984

With a hearty laugh and wide smile, Warlimpirrnga reveals what he thought when he first saw McMahon. "We were sitting down, I saw a whitefella, he was so white," he says. "'This bloke is white, this one,' I thought. 'He is white, this bloke.'"

McMahon did not want to put the group under any pressure to join the community, but he witnessed the moment they were persuaded. "It was unthinkable that they would stay out there because the modern world was so seductive. One of the fellows suggested, 'Give them a taste of the sugar and they'll be in for sure.'"

Indeed, the taste of sugar had a big impact on the Pintupi Nine and it is this aspect of their story which now animates them most. "I tasted the sugar, we didn't know what it was, but it was so sweet. I tasted the sugar and it tasted so sweet - like the Kulun Kulun flower. My mother tasted it and it was so sweet. It was good," says Warlimpirrnga.

Image copyright ALAna Mahony Image caption Yukultji making moigeba - a "damper" (a kind of bread) made with black and brown seeds

Image copyright ALAna Mahony Image caption The family ground seed on ancient grinding stones

Warlimpirrnga had a choice to make. If he decided to take his family into Kiwirrkurra Community, life as they had always known it would change forever. They would no longer walk from sunrise to sunset looking for water and food. "My brother Joseph, Freddy West and I were talking. 'We're taking you with us,' they said. 'We're going to take you home where there is more food and water.' I was listening," says Warlimpirrnga. "I thought about it for a while and I said, 'Yes, take us, we've been sitting out a long time with no-one else around.'"

We've been sitting out a long time with no-one else around Warlimpirrnga Tjapaltjarri, Leader of the Pintupi Nine

By the time the Nine reached Kiwirrkurra, new bonds had been formed. One of the search party, Freddy West, an elder of high status, had married Takariya before they even arrived - she was only a teenager at the time. "Freddy has taken one of the women as his fourth wife and everyone is amazed by how quick he was," McMahon wrote in his diary.

Aboriginal tradition has strict rules surrounding marriage. At birth you are given a skin group, which is determined by the skin groups of your parents. This determines who you are allowed to marry and is used to prevent incestuous relationships.

Warlimpirrnga does not regret deciding to leave the bush for community life. "As we came into Kiwirrkurra, I saw my nephew and niece and all the people in the community started crying when they saw us, because they knew we were family. They looked after us, they kept us, and they taught us. I got used to them. Over time I felt that I was with family together in Kiwirrkurra community and we were the same. I was happy to be with them now."

Yalti says it took a while to adjust to her new life. "We would go to the store and take flour, tin-meat and sugar. We walked out and didn't pay. We didn't know - we were bush-people. Our families would give us money and we would dig a hole and bury it. We didn't know what to do with it," she says.

The new food was also bewildering. "I cooked a potato on the campfire and it tasted good. I put an orange on the fire and it got burnt, burnt, burnt! I thought I had to move it around in the ashes, but instead the orange got really black," says Yalti.

Despite the challenges, McMahon remembers they had a terrific sense of humour. "One funny thing that happened. To do the water pipe I had to cut into the main - this was a fair amount of pressure, water spurted, everyone laughed together."

Image copyright ALAna Mahony Image caption Charlie McMahon - today the didgeridoo player lives in the Blue Mountains

Adjusting to community life was not easy for all members of the family. One brother, Payirti, returned to the bush soon after arriving at Kiwirrkurra. The family does not talk about him, but other people say different things - that he is living in a different community, or that he visits Alice Springs under a different name.

McMahon has his own thoughts on why Payirti turned back. "He was in there for about two months but even when he was there he was going off on his own. He was getting away from the place… I think he couldn't handle human conflict. The strife that was happening between families and individuals that was commonplace in Kiwirrkurra - that's why he went. He just couldn't handle the stress of it and went back. I heard stories that he had gone in to the sky... mythological kind of thing," he says.

The Pintupi Nine's story underlines how young modern-day Australia is and its vastness.

The Pintupi were some of the toughest and most skilled survivors on the planet, and by passing down their survival skills from one generation to the next, they managed to occupy this part of the world, uninterrupted, for tens of thousands of years.

Image copyright ALAna Mahony Image caption Takariya and a blue-tongued lizard catch

Community life is, in some ways, easier than their previous nomadic existence, but it also exposed them to nastier aspects of the modern world. When they came out of the desert they were examined by a doctor and found to be incredibly fit and healthy, without an "ounce of fat", but in the Aboriginal communities of Western Australia diabetes and obesity are rife. McMahon remembers how quickly they succumbed to "whitefella" diseases like the common cold. Alcoholism is a problem in the Western Desert and paint- and petrol-sniffing were too, for a number of years. All have touched the Pintupi Nine siblings in one way or another.

The last nomads?

The Pintupi Nine may not have been the very last to give up a traditional life in the outback - in October 1986 a nomadic group of seven reportedly walked out of the Great Victoria Desert - it is unclear how aware they were of modern society. A government report praises them for surviving in "one of the most harsh and remote places in the world".

Warlimpirrnga, Takariya, Yalti and Yukultji still live between Kiwirrkurra and Kintore communities. Two brothers, Walala and Thomas, are both living in Alice Springs. The old ladies have passed away. All the siblings apart from Payirti are artists - Warlimpirrnga, Walala, and Thomas have gained international recognition as the Tjapaltjarri Brothers, and in 2007 Warlimpirrnga was described as "one of the greatest painters of the desert". Yukultji too has had exhibitions in Sydney and New York.

The land still holds as strong a bond for Yukultji today as it did 30 years ago, and during a trip to Lake Mackay she is delighted to come across a Minkelbar plant - a popular bush plant which acts as a mild sedative. "Lake Mackay is my country, my home, my dreamtime stories, my birthplace," she says. "This is my place, my country. I grew up around Lake Mackay. This is where I was born."

Earlier in the year, the Pintupi community signed an agreement that turned 4.2 million hectares (16,200 sq miles) of their traditional land into an Indigenous Protected Area (IPA). The Kiwirrkurra IPA is now part of the largest protected zone of arid land on Earth. "We have been looking after country for thousands of years, and we still do so today," the traditional owners declare. "We came back here because country is not healthy without us. We make it palya (good)."

Image copyright Alana Mahony Image caption Kiwirrkurra Community

Additional reporting by Safia Desai.

The Pintupi Nine's story was featured on Outlook on the BBC World Service Listen to the interview again on iPlayer or get the Outlook podcast.

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