What is Pando? A guide to one of Utah’s most unassuming natural wonders.

The world’s most massive living organism has been regenerating itself over thousands of years in Fishlake National Forest.

(Leah Hogsten | The Salt Lake Tribune) Pando is located in the Fishlake National Forest, as captured on July 26, 2023.

Utah is full of natural wonders, from its iconic Delicate Arch and Bryce Canyon’s otherworldly hoodoo spires, to the Wasatch Range’s craggy peaks and its capital city’s namesake Great Salt Lake.

Another is more unassuming: a stand of aspens in south-central Utah near the state’s largest natural mountain lake. The stand is a single organism called Pando, and much ado has been made about this collection of trees.

Even before Utah State University’s Karen Mock and other researchers proved Pando was a single organism in 2008, she said it was “famous.”

But more recently, Pando’s health appears in jeopardy. Here is what you need to know about this superlative organism and how groups are trying to save it:

What is Pando?

(Leah Hogsten | The Salt Lake Tribune) State Route 25 cuts through Fishlake National Forest and the middle of Pando, July 26, 2023.

Pando, Latin for “I spread,” is a quaking aspen clonal colony located in Utah’s Fishlake National Forest, near the shores of Fish Lake, Utah’s largest natural mountain lake. State Route 25 runs right through the aspen stand.

While the organism looks like thousands of individual trees, they are all the same organism, comprised of the same DNA regenerated over thousands of years into new suckers, or stems, that grow to replace the older ones. Much of Pando shares a colossal root system, and the parts that don’t connect are still genetic clones.

For instance, when tree leaves begin to change color in the fall, all of Pando will turn at once.

It spans across 106 acres and weighs more than 13 million pounds, and has inspired people for decades, if not longer, bringing up philosophical questions about individuality, mortality and change.

Ironically, this superlative organism is also a microcosm of problems facing aspen elsewhere, and research there could help inform how to better sustain this keystone species.

Is Pando dying?

(Leah Hogsten | The Salt Lake Tribune) Pando, a quaking aspen colony, is the world's most massive living organism, at more than 13 million pounds.

Pando’s regeneration began to slow decades go, according to research by Paul Rogers, an adjunct professor at Utah State University and the director of the Western Aspen Alliance.

His research has also shown that different parts of Pando are regenerating better than others, based on fencing.

Parts of the stand within fencing show a healthy mix of differently aged stems. Parts within previously damaged, since-repaired fencing have too many young trees and not enough that are older or middle-aged. And in portions of Pando that are not fenced, mature trees are aging out and dying while new stems are not regenerating, because they become food for deer and livestock.

Does that mean more fences are the answer to save Pando? Rogers doesn’t think so.

[Read more: Once given a death sentence, Utah’s Pando aspen grove has ‘come a long way’]

Rogers wrote in a 2022 paper that agencies must work together to control livestock and deer grazing at Pando if they want it to survive. They can’t only focus on “control-based conservation.”

“Current browsing pressure, alongside increasing human traffic, forecasts a bleak future for Pando,” he wrote.

(Leah Hogsten | The Salt Lake Tribune) Utah Division of Wildlife Resources biologists from left, Morgan Hinton, Kyle Christensen and Mike Wardle, check the vitals, age and health of a 6-year-old mule deer prior to tagging and placing a GPS transmitter collar on the doe that was foraging near Pando, July 26, 2023.

But there is room for hope, at least in the short term. The U.S. Forest Service’s Terry Holsclaw said in an email that most of the stand — about 90% — appears to be recovering.

It also seems that Rogers’ wish for multi-agency collaboration is happening too. Utah’s Division of Wildlife Resources recently sent biologists to Pando to put tracking collars on mule deer near the stand to figure out how often they are grazing on the organism’s young stems — and what wildlife officials should do about it.

The Forest Service also approved a plan to install additional fencing, decommission some roads and stop cattle grazing within and near Pando.

How Pando will fair longterm amid a warming climate and threats from disease is less clear, Mock said.

What’s bigger than Pando?

Guinness World Records classifies an Australian seagrass meadow as the largest living organism. The Shark Bay posidonia australis seagrass is 20,000 hectares — more than 49,400 acres.

It took the crown from Oregon’s “Humongous Fungus,” a type of honey mushroom that sprawls across 965 hectares, or about 2,385 acres.

Pando, however, is technically the most massive known organism, at more than 13 million pounds.

Adding to the intrigue: There are likely even larger aspen clones than Pando, said Mock, department head of Utah State University’s Quinney College of Natural Resources. We just haven’t discovered them yet.

How to see Pando

(Leah Hogsten | The Salt Lake Tribune) Signs mark the entrance to Pando off Highway 25.

People have been visiting Fish Lake for generations, resting in the shade of Pando and other aspen stands, said Dan Child, public services staff officer with the Forest Service.

Now is no different.

Stop to see Pando on pull-offs along State Route 25. Its boundaries are bookended by two metal signs. You can also free roam through portions of the stand. If you enter through a gate, make sure to close it.

And don’t carve into the aspen trees.

“A tree’s bark is like your skin. Carving into a live tree can cause infections and access for insect and fungus to enter a healthy stem,” Child said. “Please do not carve, chop, or nail into the trees.”

There are a few nearby lodges and public and private cabins; established campgrounds; and some dispersed camping in or near parts of the clone. Public cabins and camp sites can be reserved at recreation.gov.

If you can’t take a trip to visit Pando, you can look at images of the aspen stand on citizen science group Friends of Pando’s website. Their volunteers, along with help from Snow College, completed a photographic survey of the stand to help track its changes and to show it off to those unable to see it in-person.