Pando By the Numbers
An ancient wonder operating on an extraordinary scale. Gather facts, figures and insights that describe how this trembling giant works – from the people who work to protect and care for Pando.
Did you read a story or hear something about Pando worries you? Visit our Science Communication Center to learn more.
Friends of Pando FAQ's
Table of Contents
What makes Pando the largest tree of any kind?
Pando is the largest tree in the world in three distinct ways: by weight (13.2 million pounds), by land mass (106 acres), and by species (the largest Trembling Aspen clone verified by genetic testing). No other tree beats Pando in any single one of these categories, and Pando holds the record in all three at once.
Sources: Kemperman & Barnes 1976, Canadian Journal of Botany 54(22) | DeWoody et al. 2008, Western North American Naturalist 68(4)
How big is Pando?
Pando spans 106 acres and weighs over 13.2 million pounds.
Sources: Kemperman & Barnes 1976, Canadian Journal of Botany 54(22) | DeWoody et al. 2008, Western North American Naturalist 68(4)
I thought the General Sherman Tree was the largest tree?
Pando outweighs General Sherman, the largest Sequoia, by 3 times and covers 100 times more land. Coast redwoods are the tallest single-stem trees and Sequoias the heaviest single-stem trees, but neither is a single connected organism the way Pando is.
Source: Science Communication Center
How do we know for sure Pando is the largest tree of any kind?
Genetic testing confirmed Pando is a single organism spanning 106 acres. Between 2006 and 2008, U.S. Forest Service researchers and independent scientists collected plant tissue samples across the grove and verified they were all genetically identical, proving Pando operates as one connected tree rather than a collection of separate ones.
Sources: DeWoody et al. 2008, Western North American Naturalist 68(4)
How many stems (ramets or trunks) make up Pando?
Pando is estimated to have about 47,000 stems, based on a 1976 study that combined aerial mapping with on-the-ground sample counts. Researchers mapped Pando’s boundary from the air, then walked sample plots to measure stem density — about 440 per acre — and applied that average across the full 106.8 acres. It’s a careful estimate, not an exact count; Friends of Pando is working on a full census through its Data Store to get a more precise number.
Sources: Kemperman & Barnes 1976, Canadian Journal of Botany 54(22) | Friends of Pando Data Store
How old is Pando?
Pando is at least 9,000 years old, and no method available today can fix a firm upper limit on its age.
The 9,000-year floor comes from radiocarbon-dated charcoal showing aspen has grown continuously on this exact spot since the early Holocene. Because the most recent glacial advance on the Fish Lake Plateau dates to roughly 21,100 years ago, a post-glacial establishment — sometime in the range of 9,000 to 16,000 years ago — is the reading best supported by the landscape itself.
A newer method has proposed older figures. Pineau and colleagues counted naturally accumulated mutations in Pando’s DNA and estimated a range of 12,000 to 37,000 years. That work is published as a reviewed preprint and has not completed peer review; eLife’s reviewers rated the supporting evidence incomplete, citing the sequencing depth used. The upper end of that range would also place Pando’s origin before the last glacial maximum, which the local geologic record does not currently support. Friends of Pando uses the conservative, charcoal-based figure while the newer research is evaluated.
Sources: Novák et al. 2022, Forest Ecology and Management 521:120436 | A Geologic History of Fishlake, Pando’s Home | Pineau et al., “Mosaic of Somatic Mutations in One of Earth’s Largest Organisms, Pando” (eLife Reviewed Preprint, 2026)
But I read Pando was 80,000 years old?
Pando is not 80,000 years old — that figure is a persistent but incorrect claim. It originated on a Bryce Canyon National Park web page in the 1990s, was never based on any test of Pando’s age, and the park service removed it in 2023.
Pando is at least 9,000 years old, and no method available today can fix a firm upper limit on its age. The landscape itself points to a post-glacial establishment, most likely between 9,000 and 16,000 years ago. A newer genetic method has proposed older figures, but that work has not completed peer review.
Sources: Novák et al. 2022, Forest Ecology and Management 521:120436 | Pineau et al., eLife Reviewed Preprint (2026)
How big is Pando's root system?
A rapid field estimate is that Pando’s root system is roughly 12,000 miles long, but this is only an estimate. Today, little is known about Pando’s underground structures. Friends of Pando has proposed that we may be able to send pulses of sound to map the root to get a better idea.
How much sunlight does Pando need?
Pando’s landmass receives enough sunlight to power 70,000 homes a year, or about 191 homes a day, according to a study commissioned by Friends of Pando. This estimate was developed using “Solar Anywhere” software from Clean Power Research.
Aspen are shade intolerant. So, unlike a single tree, as a clone, the entire canopy of all the trunks of Pando gather light. A single tree has a single canopy, with Pando, all the trunks form that “single” canopy.
Sources: Independent Researcher using “Solar Anywhere” software from Clean Power Research | 2025 Friends of Pando Brochure
If I had to water Pando, how much water would I need?
The standard gardener’s rule for watering trees is 10 gallons of water per inch of trunk diameter. Pando’s 47,000 trunks range between 4 and up to 18 inches thick, when we work to average that, it means it could take around 8.46 million gallons of water every three weeks to water Pando during peak growing season; June through September.
This is only a gardeners estimate. So it is important to point out that as a clone, Pando can store lots of water on its own, and can coordinate water more efficiently than a single tree, so the number may be a smaller.
If Pando needs that much water, where is it getting it from?
Pando lives along a basin wall of the Fish Lake Basin. This means it gets its water from drainage, runoff, natural springs, snowmelt, and summer rains.
Nearby Fish Lake itself spans nearly 5 square miles and reaches depths of up to 130 feet meaning it gets way more water than falls from the sky. Fishlake National Forest estimates that Fish lake gets about 70% of its water through underground springs – water collecting in the basin soaks into the ground and moves downward toward the lake, suggesting Pando gets most of its water from below ground.
Friends of Pando is developing a hydrology model to better understand water flow in Pando, and will post updates as they become available via our Pando Data Store.
Source: Friends of Pando Data Store
How many leaves does Pando have?
Friends of Pando estimates that Pando features between 1 to 1.5 billion leaves. This number is based on general estimates for Pando’s leaf size (around 3 inches), the typical single trunk canopy width (30 feet), and some conservative math on how many trunks are active.
Sources: Friends of Pando | Omni Leaf Calculator
How much pressure does Pando's root system need to move water and sugar across the tree?
There’s no direct field measurement of this today, but Friends of Pando built a hypothetical vascular model to estimate it. We looked at Pando’s root network as a single connected vascular system that has to move water up, and sugars across 106 acres with 300 feet of elevation change. Using this data, we estimated Pando would need to maintain about 29 pounds of Pressure Per Square inch (PSI) to move everything around. By way of analogy, that is in the same range of pressure a bike or car tire needs!
Sources: Friends of Pando internal vascular model review
How many Calories of energy does Pando's leaf canopy produce each year?
Pando’s estimated 1 billion leaves produce roughly 1.2 to 5.3 billion Calories of energy annually according to standard energy models. By way of analogy, this would “feed” between 1,315 and 5,800 people a year. This is an estimate based on peer-reviewed work on Populus tremuloides leaf-mass data which we refine as we get better data.
Sources: Baird, Anderegg, Lacey, HilleRisLambers & Van Volkenburgh, “Comparative leaf growth strategies… in Populus tremuloides,” Tree Physiology 37(9), 2017 | Song, Hou, Li, Zhang & He, “Leaf Caloric Value from Tropical to Cold-Temperate Forests,” PLOS ONE, 2016
Does Pando get energy from anything besides its leaves?
Yes — from its bark. Pando’s bark contains chlorophyll and can photosynthesize on its own, even through winter when the tree has no leaves.
This “corticular photosynthesis” accounts for an estimated 5–10% of the tree’s total photosynthetic capacity and reclaims 50–75% of the carbon dioxide its stems would otherwise lose to respiration. On a surface-area basis, aspen bark’s annual carbon fixation rivals that of evergreen conifer needles — a rare trait among broadleaf trees that likely helps Pando’s stems survive harsh winters at 8,900 feet.
Sources: Schaedle & Foote, “Seasonal Changes in the Photosynthetic Capacity of Populus tremuloides Bark,” Forest Science 17, 1971 | Foote & Schaedle, “Contribution of Aspen Bark Photosynthesis to the Energy Balance of the Stem,” Forest Science 24, 1978
How much CO2 does Pando absorb each year?
Pando’s canopy is estimated to absorb about 530,000 lbs of CO2 annually, based on a typical temperate-forest sequestration rate of ~2.5 tons of CO2 per acre applied across its 106 acres. This corrects an earlier published figure of 148,000 lbs/year, which appears to have been calculated per-tree rather than scaled to Pando’s full canopy.
Sources: CO2 sequestration rate — standard temperate-forest estimate (~2.5 tons/acre/year), applied to Pando’s 106-acre landmass
How much oxygen does Pando produce?
Pando produces an estimated 385,000 lbs of oxygen per year, based on its CO2 absorption converted through standard photosynthesis stoichiometry. That’s enough to fully meet the annual oxygen needs of about 236 people. Measured against the roughly 11,643 people living in the towns nearest Pando — Richfield, Monroe, Loa, Koosharem, and Fremont — Pando’s output works out to roughly 1 in every 49 breaths taken in the area.
Sources: See “How much CO2 does Pando absorb each year?” above; conversion — standard photosynthesis stoichiometry | U.S. Census 2020: Richfield, Monroe, Loa, Koosharem, Fremont
Friends of Pando FAQ Collection
Answers from the people who work to care for Pando every day
Friends of Pando is dedicated and working to educate the public, support research and preservation efforts and inspire stewardship of Pando, the world’s largest tree.
Friends of Pando is a proud partner of Pando’s public land stewards, Fishlake National Forest of the U.S. Forest Service, Department of Agriculture. Learn more about our partnership.
Friends of Pando and its partners are equal opportunity employers.
Just $18 a month supports work to ensure Pando can be enjoyed for generations to come. Make a one-time or, recurring tax deductible donation today.
Friends of Pando
PO Box 12
Richfield, UT, 84701
Phone: 435-633-1893
IRS EIN: 87-3958681
