The oldest tree on Earth was nearly 5,000 years old, and in 1964 a researcher cut it down by accident

High in the cold, bare mountains of the American West grow the bristlecone pine trees, the oldest living things on the planet. The story of the very oldest of them is one of the saddest accidents in the history of science.

A bristlecone pine can live for thousands of years on a windswept mountain. Illustration: Watts & Wild.

We measure most lives in decades, and even the grandest old trees in years or centuries.

A few trees keep a far longer kind of time, counting their lives in thousands of years.

What is the oldest tree on Earth? The oldest individual trees on Earth are bristlecone pines growing in the mountains of California and Nevada, several of which are more than 4,800 years old. The very oldest one ever recorded, a tree later named Prometheus, was cut down in 1964 before anyone knew how old it was.

The oldest living things on Earth

Bristlecone pines grow high up in a handful of dry mountain ranges in the western United States.

Up there the conditions are brutal, with thin soil, fierce wind, bitter cold and very little water.

Strangely, that hardship is the secret to their long lives, because it forces the tree to grow incredibly slowly.

The wood it lays down is dense and packed with resin, which makes it resist rot, insects and disease for thousands of years.

Many of these gnarled survivors were already ancient when the pyramids of Egypt were being built.

How a tree lives for millennia

Part of the trick is that a bristlecone does not need to stay whole to stay alive.

Much of an ancient tree can be dead, bare wood, with just a thin strip of living bark feeding a few green branches.

That living sliver can keep the tree going for centuries even as the rest weathers into sculpture.

Inside the trunk, each year lays down a growth ring, so the wood becomes a private diary of climate stretching back millennia.

It is exactly that record of rings that drew scientists up the mountains in the first place.

The tree called Prometheus

In 1964, a young geographer named Donald Currey was studying the climate history written in the rings of bristlecone pines on Wheeler Peak in Nevada.

To read a tree's rings, researchers normally bore out a thin pencil of wood with a tool, leaving the tree alive.

Currey's borer reportedly broke or got stuck inside one particular old tree, and with permission from the US Forest Service the tree was cut down so its full cross-section could be studied.

Only when the rings were counted did the scale of the loss sink in, because the tree, later named Prometheus, held around 4,862 rings.

It was almost certainly the oldest known living thing on Earth, and it had been felled in the very act of studying it.

Methuselah and the secret groves

The oldest verified living tree today is another bristlecone, known as Methuselah, thought to be over 4,850 years old in California's White Mountains.

To protect it from souvenir hunters and vandals, its exact location is kept a closely guarded secret.

Researchers have even reported an unnamed bristlecone older still, though it too is kept anonymous.

The lesson of Prometheus is written into how these elders are now treated, hidden rather than advertised.

Sometimes the kindest thing we can do for a wonder is to refuse to tell anyone exactly where it is.

The honest catch

The popular story of the man who killed the oldest tree is a little harsher than the facts.

The Forest Service approved the cutting, and at the time nobody realised the tree would turn out to be the oldest of all.

The exact age has been refined by researchers over the years, and the round number of nearly 5,000 years is an estimate, not a birthday.

Donald Currey went on to a long scientific career, but the felling of Prometheus followed him for the rest of his life.

And every claim of an oldest tree really means the oldest one we happen to have found, with others perhaps still standing unknown.

The bristlecone pine is a reminder that some living things keep time on a scale that makes whole civilisations look brief.

It belongs with the other quiet champions of deep time we have followed, from the single aspen that is a forest unto itself to the shark that may live four centuries.

If a tree can outlive empires only to fall to a stuck drill bit, what does Prometheus teach us about how carefully we should treat the oldest living things, and would you want to know where Methuselah stands? Tell us in the comments.