The lonely death of Chris McCandless inspired a book and Sean Penn's film Into the Wild. Now, more than 20 years on, hundreds follow in the idealist's trail – but locals wonder if it has all gone too far

The old bus in which Chris McCandless died in 1992 in the interior of Alaska – made famous in Jon Krakauer's book Into the Wild and later in the Sean Penn film of the same name – long ago lost its windows to souvenir hunters.

A plaque inside the bus, installed by his family, commemorates his life. A recent visitor describes the site as a pigsty.

The same reasons that cost McCandless his life, trapped without enough food on the wrong side of a Teklanika river in full spate from summer meltwater, makes it a dangerous place to approach.

Last year a dozen "pilgrims", as residents of the nearby town of Healy disparagingly label the hundreds who have been drawn to the bus each year since Penn's film was first screened in 2007, needed to be rescued by park authorities, local people and state troopers. So far one visitor to Bus 142 has died, a 29-year-old Swiss woman, Claire Ackerman, who drowned in the river. Others have had close escapes.

All of which has fuelled a simmering debate – how best to deal with the morbid magnetic pull exerted by the fascination with McCandless.

The McCandless story is well known: how the 24-year-old hiker, born in California, raised in Virginia, abandoned his safe suburban upbringing, donating $24,000 in savings to charity and styling himself Alexander Supertramp, and set off on a two-year hitchhiking journey that ended with his death in the bus.

Interest is unlikely to wane any time soon. A book by his sister, Carine, is due to be published this autumn, while a mockup of the Fairbanks City Transit bus, built for Penn's film, is a tourist attraction in its own right in Healy, bought by a local brewery. On one side are those who believe the bus should be removed, on the other a costly proposal to build a footbridge across the river at a place where it narrows.

If evidence were needed of both the appeal of the story and the place where McCandless died in his sleeping bag, to be found later by moose hunters, there is ample evidence online. There are blogs dedicated to his story and pictures posted of "pilgrims" seated in the same pose in which McCandless photographed himself outside the bus.

"There's a pretty steady trickle all summer," says Jon Nierenberg, who owns the EarthSong lodge off the Stampede Road, which most visitors use to get to the bus.

"There are different types, but for the most passionate – the ones we locals call pilgrims – it is a quasi-religious thing. They idealise McCandless. Some of the stuff they write in the journals [at the bus] is hair-raising."

A very few, Nierenberg suspects, have gone a step further by camping next to the bus and depriving themselves of food.

"We had one tall skinny guy who had been out there for a week or two who staggered, swaying on his feet, into our coffee shop. We helped him out, then sent him on his way."

Diana Saverin secured a writing grant to study the phenomenon of the pilgrims which she described in a long article for Outside magazine in December after becoming fascinated by McCandless's story during her first visit to the area in 2011. In The Chris McCandless Obsession Problem she recalls: "We soon felt the story's pull. I was 20, Jonathan [her travelling companion] was 22, and McCandless's uninhibited adventures spoke to both of us."

An encounter with the French boyfriend of Ackerman, who had returned a year after her drowning, marked the beginning of her interest in those who were drawn to the bus. The issue was dramatically underlined when, as she walked along the trail herself, she encountered three "pilgrims" who had been trapped by the river for a day and a half and who had sent for help.

Krakauer's book, Saverin believes, has accrued a growing cultural significance as one of those cult books on to which readers project their own preoccupations. In that sense it has garnered a status like The Catcher in the Rye or On The Road.

Its closest equivalent, however, is Henry David Thoreau's Walden – the transcendentalist and natural philosopher's chronicle of his own experiment in self-sufficiency between 1845 and 1847 in a one-room cabin in Massachusetts, a replica of which is now also a popular tourist site. The comparison is unsurprising, since Thoreau, as Krakauer notes in Into the Wild, was a writer who fascinated McCandless, along with Leo Tolstoy and Jack London.

But what of the "pilgrims" that Saverin met and their motivation? "The people I encountered would always talk about freedom" she said. "I would ask, what does that mean? I had a sense that it represented a catch-all. It represented an idea of what people might want to do or be. I met one man, a consultant, who had just had a baby and who wanted to change his life to be a carpenter – but couldn't, so took a week to visit the bus. People see McCandless as someone who just went and 'did it'."

She finds it ironic that what the "pilgrims" hanker after – McCandless's perceived idealised rejection of the modern world to forge his own path – has become a well-worn trail. And unlike Thoreau, Saverin also points out, McCandless did not construct his own philosophy – the "insights" that readers find being channelled by Krakauer.

One of the fiercest critics of the McCandless myth – and all that it represents – is Craig Medred, who writes for the online Alaska Dispatch, most recently in September in an article headlined The beatification of Chris McCandless.

"Thanks to the magic of words," writes Medred, "the poacher Chris McCandless was transformed in his afterlife into some sort of poor, admirable romantic soul lost in the wilds of Alaska, and now appears on the verge of becoming some sort of beloved vampire.

"Given the way things are going, the dead McCandless is sure to live on longer than the live McCandless, who starved to death in Interior Alaska because he wasn't quite successful enough as a poacher."

And Medred's conclusion takes a swipe at his disciples. "More than 20 years later, it is richly ironic to think of some self-involved urban Americans, people more detached from nature than any society of humans in history, worshipping the noble, suicidal narcissist, the bum, thief and poacher Chris McCandless."

Kris Fister, a spokeswoman for the Denali National Park nearby, whose rangers have been called in to help "pilgrims' who become trapped on the wrong side of the river, frames the same question regarding those who get into trouble in more moderate terms.

"The water gets high in the river – the same issue that Chris McCandless had to deal with. People don't have enough food. The question I would ask is: you read the book or saw the film. What is your disconnect? There are places you can cross if you go downstream. But often these are people who do not feel comfortable navigating. Often people don't have the experience or the equipment. The summer before last there was one gentleman we had to help on two occasions."

For some, at least, the pilgrimage to the 142 bus, far from providing an epiphany, has been the source of disillusionment. Among these is Chris Ingram, who wrote an essay on his own experience for the Christopher McCandless website. Arriving a few days after Ackerman's drowning, he had planned, he recounts, to hike the trail to the bus "to have my own survival experience in Wild Alaska and to pay my respects to a person I adored and admired".

Reaching the raging river where rangers were still finishing their investigation into Ackerman's death, Ingram decided to turn back, his view of Bus 142 as the "mecca of McCandless followers" radically transformed.

"Perhaps," he wrote of his own experience, "we are over-enchanted by the zeal of his story, over-sympathetic, feeling a sense that we can relate, or perhaps a Hollywood movie has mesmerised, idealised and over-romanticised our thoughts and beliefs beyond our own lives that we fantasise away from them.

"I had an ample amount of time along the trail to contemplate Chris's story, as well as my own life. The wilderness is a poor place to put your worries, your concerns, your dreams, your hopes, thoughts, wishes and happinesses. The wild simply is just that, wild. Unchanging, unforgiving, it knows nor cares not for your own life. It exists on its own, unaffected by the dreams or cares of man. It kills the unprepared and unaware."

As for the fate of the bus itself, Fister's own view is that, with the vehicle rotting, nature will eventually reclaim it.