MARSHALL: It’s some of the most hostile terrain on earth. The Owen Stanleys form a barrier between P.N.G’s north and south coast breached only by a 96 kilometre path that snakes through the mountains. This is the trail that became known as the Kokoda Track to the Australian soldiers who fought here.

In 1942 the invading Japanese chose this route in their push towards Australia but what made the Kokoda Trail famous were the extraordinary efforts by the Australian diggers to eventually repel them. Now, new generations of Australians venerate this track while others come here for the ultimate endurance test.

FRANK TAYLOR: [Briefing group] Biscuits plain, biscuits beef. Three packets each.

MARSHALL: This is where it all begins, poolside at a motel in Port Moresby and former West Australian Police Inspector Frank Taylor is preparing his latest group for the trek of their lives.

FRANK TAYLOR: [Briefing group] Don’t eat the two minute noodles until we tell you.

MARSHALL: He’s one of a least a dozen tour operators who ply the tail. Frank Taylor’s been running treks for twenty years. He’ll offer his clients a detailed commentary of history along the way.

FRANK TAYLOR: [Briefing group] It’s going to be tough enough, it doesn’t have to be a super arduous military type, you know, let’s push you to the extreme.

MARSHALL: Jenny Di Giandomenico is the only woman in the group. She signed up for the physical challenge.

FRANK TAYLOR: [Briefing group] If we flog you it’s a red blur and everything we’re trying to do is just counter productive.

JENNY DI GIANDOMENICO: I’m from an Italian background so like I really, apart from the basics at school don’t have that connection. Lots of blokes around, just you know, I’ll be fine.

MARSHALL: This food will have to last Jenny and her four paying colleagues for ten days. A team of local carriers led by Chris Aubi will be there every step of the way.

CHRIS AUBI: They can make it all the way to the finish line.

MARSHALL: What tells you that?

CHRIS AUBI: Well by the look of them, they are fit. They can do it.

MARSHALL: It was a very different trek for the diggers of 1942. A ferocious Japanese from the north had them back peddling to the doorstep of Port Moresby. Outgunned and out numbered, under trained and ill equipped, the Diggers also fought disease and starvation in their remarkable efforts to resist a relentless enemy. It was a feat that would become an inspiration for future generations and part of the folklore of a nation.

It’s hot, it’s muggy and it’s slippery and it can take anywhere between 6 to 10 days to walk this muddy track yet over the past few years the number of adventurers willing to put themselves through this ordeal has doubled. Yet as resilient as this jungle seems, this place is changing because of its modern day popularity.

Last year, two and a half thousand walkers plodded through here. Like the popular pilgrimage to Gallipoli, Kokoda has become a magnet for those who want to acknowledge a defining event in our history. They come here in school groups and in professional sports teams, corporate leaders use it as a bonding session. Others just want to say they’ve done it.

LES BROWNING: [Trekker] It is just relentless. You go up a hill and you think beauty I’ve got to the top but no you haven’t. There’s another one after it, then another one after it. And then you’re going down, it takes forever as well. It’s a very hard physical thing to do.

MARSHALL: Three days into the walk and Frank’s group is battling the excruciating ups and the daunting downs of the same track that sapped the spirit of Australians and Japanese alike.

At this village Frank’s party encounters a much larger group coming the other way. They must share a tiny village and limited space to sleep. Frank’s carriers take all rubbish with them but other groups don’t have the same policy.

FRANK TAYLOR: The toilet and rubbish thing is reaching a problem stage at the moment and that’s anti social as far as the villagers are concerned because it impacts on them.

MARSHALL: Tonight’s a squeeze here but in other villages there are too many guesthouses as locals vie for passing trade.

FRANK TAYLOR: There’s also the competition between the rest houses and so forth and if people are not thoughtful on how they manage that, then you’ll end up with more conflict - I can see that quite easily, competition reaching violence because that’s a tool of resolution in this country.

MARSHALL: This week there’s another group of arrivals on the Kokoda Trail. The villagers of Menari have turned out to greet a charter aircraft with a prized cargo. A load of day old chickens has arrived. It’s a delivery from a new government agency set up to manage the trail. The Kokoda Track Authority extracts the equivalent of $80 from each foreign trekker. The money is meant to improve facilities for the walkers and help villages along the way.

In a country hamstrung by corruption there’s a great deal of suspicion here. There’s no suggestion the KTA is dishonest, but not all the money is filtering through. Forty per cent of the takings are swallowed up in administration and that’s something that grates with village leaders like Saii Faole.

SAII FAOLE: Life was changed when the walkers came in. I really don’t want the KTA to take over the Kokoda Trail, because we are the landowners and we want to look after our land, and we want to be the boss of our land, and let the walkers come in. We are welcoming them. We are happy.

ARCHIVE FOOTAGE: The care and consideration shown for the wounded by the natives has won the complete admiration of the troops. With them the black skinned boys are white.

MARSHALL: In 1942 they earned a reputation for their muscle. They were the so called “fuzzy wuzzy angels” who fed the Australian war machine and evacuated its casualities along the trail. Today just a few remain.

FRANK TAYLOR: Guys, my mate Bokkoy and if you come and introduce yourselves I’ll try and tell you a little bit about my friend here.

He was probably round about 14 years of age when the fighting took place here. If they had hair under their arm as far as they were concerned they were old enough to carry.

MARSHALL: These days their sons and grandsons carry for the Australians in an industry that is the Kokoda Trail.

FRANK TAYLOR: It’s a family commitment which suits me because I get steady workers and guys that want to work and I’ll often have guys that have done their sums and work out that three or four trips and they have paid for a number of their children to be educated for the year.

MARSHALL: It’s paying off for chief carrier Chris Aubi. Every step along the trail, is more money earned to send his children to school in Port Moresby.

CHRIS AUBI: Well it is beneficial for the villagers, yeah. There’s so many people along the track now working as porters and guides and people along the track are a bit happy about that.

MARSHALL: Although the new popularity of the track has changed the lives of these people they still live off the land, but now much of their produce is sold to trekkers. Instead of the week long journey to the market, the market comes to them.

FRANK TAYLOR: You think you know just about everything there is on this campaign and there’s always something else.

MARSHALL: Concealed in the jungle are the reminders of war. Frank has taken his group to a recently uncovered network of Japanese tunnels.

FRANK TAYLOR: We’re a bit uneasy about going into them because of the risk of booby trapping.

MARSHALL: But on nearby mountains, more modern earthworks are less discreet. This gold mine in the village of Naoro provides alternative employment. Community leaders like Saii Faole welcome the new money.

SAII FAOLE: Gold money is good, because when they’re looking for gold they’re just in one area... they set up their campsite.

MARSHALL: There is another more threatening encroachment and it’s eating the jungle. Along the mountain tops there are new trails, the scars of logging activity. Selective logging has cleared vegetation to within just four kilometres of the track and to the anger of villagers, it’s getting closer.

SAII FAOLE: We don’t want the logging to come in and destroy our environment. We just want to live in a jungle.

MARSHALL: Six days into his foray into the jungle, Cairns fitter and turner Les Browning is standing up to the test. Following his father’s footsteps has been the spiritual journey he had hoped for.

LES BROWNING: I’ve got myself into a mindset of just plodding, I just put one foot after the other and don’t look at the top of the hill and keep struggling on. And of course I keep thinking of my father and the fact that he made it through so I’m almost honour bound to do the same thing you know?

JENNY DI GIANDOMENICO: It’s not an issue of being male or female, we’re just all here for you know our own individual reasons but it’s great.

MARSHALL: And surviving also is Melbourne painter and nail technician, Jenny Di Giandomenico. She came for the physical challenge but now she’s made that connection with the track’s history.

JENNY DI GIANDOMENICO: Meeting like the original fuzzy wuzzy angel, that was amazing. That really gave me a little bit more purpose of why I was here.

MARSHALL: Not since the battles of 1942 have so many people moved along this path. This is the second group of the day to entertain and be entertained in this village. There are sometimes groups of 150 descending on these tiny trek stops.

FRANK TAYLOR: If you’ve got groups that size it’s very, very hard to supervise and see that they maintain the quality of behaviour, both on the hygiene and on the social side.

MARSHALL: Many believe the Kokoda campaign saved Australia. Certainly it’s the closest land force threat we’ve ever had. Now villagers and walkers have become players in a complex enterprise that is the Kokoda Trail. The muddy track that’s etched in military folklore faces its own battle for survival from the very people who revere it.