'Touching' movie explains story behind historic photo of man holding message to world before never being seen again

The picture of a man holding his last message to the world has a truly tragic story behind it.

After graduating university in 1990, Chris McCandless decided to donate all of his savings to embark on a hike into the wilderness in two year's time.

The 24-year-old was inspired by his favourite book The Call of the Wild by Jack London, which follows a dog called Buck who is stolen from his home and sold as an Alaskan sled dog.

Buck learns to survive in the wild by fighting off his rivals and embracing his inner wolf.

Though sadly for McCandless, he was unable to survive the harsh realities of nature.

His story was adapted into a book and then a 'touching' film, which came out in 2007.

You can take a look at the trailer for Into the Wild below:

Directed by Sean Penn, the biographical drama is based on Jon Krakauer's book of the same name and follows the life of McCandless, played by Emile Hirsch.

The young man left behind his comfortable life to explore the American wilderness and seek freedom.

After donating his savings, he changed his name to Alexander Supertramp, and went on a journey across the country.

Along the way, he encountered various characters, including Jan (Catherine Keener), Ron (Hal Holbrook), and Wayne (Vince Vaughn), who impacted his outlook on life.

A photo Chris McCandless had taken of himself outside his makeshift home in the bus. (Wikimedia Commons)

However, his attempts to survive the Alaskan wilderness were not successful.

In real-life, McCandless' body was recovered by hikers who spotted it in a rusted bus where he lived. He weighed just 67lbs when he was found.

However, the reason why his story could be told to the world is because the university graduate journaled and photographed what would be his final moments.

In April 1992, he hitchhiked to Alaska with the last person to see him alive.

Electrician Jim Gallien said he was concerned by how ill-equipped McCandless was as he was advised to delay the trip, to which he refused.

All McCandless had for food was some rice, and for entertainment, a handful of books.

McCandless holding his note. (Reddit/u/frituurgarnituur)

For protection, he carried a rifle, which kickstarted his 113-day survival mission in Alaska.

After realising that his days were numbered, McCandless placed a message onto the bus which read: "Attention Possible Visitors. S.O.S. I need your help.

"I am injured, near death, and too weak to hike out. I am all alone, this is no joke. In the name of God, please remain to save me. I am out collecting berries close by and shall return this evening.

"Thank you, Chris McCandless. August?"

In the historic photo, his goodbye message to the world read: "I have had a happy life and thank the Lord.

"Goodbye and may God bless all!"

It is believed that McCandless died either from starvation or eating wild plants.