Best US forests for forest bathing: 40 ranked

Redwood National and State Parks tops our list of the best U.S. forests for forest bathing, followed by Humboldt Redwoods and Olympic National Park. Below is a list of 40, from the redwood coast to the pine flatwoods of Florida.

The order is our own judgment of how well each forest lends itself to a slow, unhurried visit: continuous shade, quiet, gentle ground, and a real route you can walk without turning it into a hike. No study has ever compared these forests against each other for health effects, so this is an editorial pick, not a measurement of what any of them does to your body.

We left tree species out of it on purpose. The science on tree chemistry is genuinely interesting, and it is covered in detail below, but current research cannot tell us whether a redwood, pine, cedar, hardwood, or Douglas-fir forest produces a larger health benefit. So the list ranks places, not trees.

Prefer the evidence before the destinations? Skip to what the research can and cannot tell you for the trials, the dose numbers, and what holds up.

Forest bathing means spending slow, attentive time in a forest and taking it in with your senses. It comes from the Japanese practice of shinrin-yoku, which translates roughly to taking in the forest atmosphere. It is not hiking. There is no distance goal and no summit.

How to read this ranking. There is no scientific system for ranking U.S. forests by their health effects, and no trial has compared these destinations head to head. This is an editorial ranking of places that appear especially well suited to the practice of forest bathing. Verify current conditions, closures, fees, and permits with the managing agency before you travel.

The 40 best U.S. forests for forest bathing

Rank	Forest	State
1	Redwood National and State Parks	California
2	Humboldt Redwoods State Park	California
3	Olympic National Park	Washington
4	Congaree National Park	South Carolina
5	Idaho Panhandle National Forests	Idaho
6	Sequoia and Kings Canyon National Parks	California
7	Great Smoky Mountains National Park	Tennessee and North Carolina
8	Monongahela National Forest	West Virginia
9	Porcupine Mountains Wilderness State Park	Michigan
10	Coconino and Kaibab National Forests	Arizona
11	Allegheny National Forest	Pennsylvania
12	Willamette National Forest	Oregon
13	Siuslaw National Forest	Oregon
14	Superior National Forest	Minnesota
15	Tongass National Forest	Alaska
16	Adirondack Park	New York
17	San Juan National Forest	Colorado
18	White Mountain National Forest	New Hampshire and Maine
19	New Jersey Pine Barrens	New Jersey
20	Lassen Volcanic National Park	California
21	Mount Rainier National Park	Washington
22	Chugach National Forest	Alaska
23	Acadia National Park	Maine
24	Pisgah National Forest	North Carolina
25	Bitterroot National Forest	Montana and Idaho
26	Ouachita National Forest	Arkansas and Oklahoma
27	Santa Fe National Forest	New Mexico
28	Lincoln National Forest	New Mexico
29	Black Hills National Forest	South Dakota and Wyoming
30	Apache-Sitgreaves National Forests	Arizona
31	Huron-Manistee National Forests	Michigan
32	Apalachicola National Forest	Florida
33	Ocala National Forest	Florida
34	Arapaho and Roosevelt National Forests	Colorado
35	Sam Houston National Forest	Texas
36	Shawnee National Forest	Illinois
37	Rogue River-Siskiyou National Forest	Oregon and California
38	Pack Forest	Washington
39	Yosemite National Park	California
40	Great Basin National Park	Nevada

Does forest bathing actually work?

The short answer is that spending time in a forest almost certainly makes you feel better, and the bigger claims made about it are far shakier. That a quiet walk in the woods lowers stress is not really in question. What is in question is the more specific, more impressive stuff you see in headlines: that forest air measurably boosts your immune system, or that invisible compounds from the trees are doing the work. Those claims rest on a handful of small studies with real problems, and the amount of those compounds you actually breathe in a forest is tiny. So enjoy the forest for what it plainly is, and be skeptical of anyone selling it as medicine.

The trend started in Japan in the 1980s, where researchers coined the term shinrin-yoku and began testing whether time in a forest changed anything measurable in the body. Most of the science quoted today traces back to that work. Here is what it does and does not show.

Stress and mood

Start with the least controversial part. People feel calmer and less anxious after time in a forest. Study after study finds it, and it matches what everyone already knows from experience. Nobody needs convincing that a quiet walk in the woods beats an afternoon in traffic.

Where the science gets shaky is when it tries to put a precise number on that feeling. In practice "stress" gets measured two ways: with questionnaires, where people rate how tense they feel, and with the body, mainly blood pressure and a stress hormone called cortisol. A 2026 review in Frontiers in Psychology by Andrade and colleagues pooled 11 forest studies and did find improvements in blood pressure and stress markers, but rated its own confidence in the size of those effects as low. That low confidence is about the exact size of the effect, not about whether it exists. The reason is worth understanding, because it comes up again and again in this field.

The individual studies did not agree on how big the effect was. Some found a large benefit, some a tiny one, some none. That kind of scatter usually means the studies were not really testing the same thing: one had people sit quietly for 15 minutes, another sent them on a multi-day trip; one measured anxiety on a questionnaire, another measured blood pressure; the groups ranged from stressed office workers to healthy students. Pool experiments that different and the average number hides more than it shows. So the takeaway is not that the calm is fake. It is that no one can hand you a reliable dose or a precise number for it.

Blood pressure shows the same thing. An earlier 2017 meta-analysis by Ideno and colleagues pooled 20 trials and found a small real drop. But it flagged a second issue that affects a lot of this research. Studies that find a positive result tend to get published, while studies that find nothing often get quietly shelved and never see print. When that happens, the published record skews toward good news, and anyone pooling only the published studies ends up with a benefit that looks bigger than the full evidence would support. The pattern in this analysis suggested exactly that: some no-effect studies were probably out there, unpublished.

Stress hormones

Cortisol is the main stress hormone your body releases. A 2019 meta-analysis by Antonelli and colleagues pooled the forest studies and found cortisol dropped after forest visits, which fits the idea that forests lower stress. The authors did note that the exact size of the drop is hard to pin down, since the studies were small and varied, the same limitation running through everything above.

Immune cells

Natural killer cells, or NK cells, are white blood cells that hunt down infected and damaged cells. This is the finding that gets stretched furthest, usually into claims that forest bathing fights cancer. It does not. No study has ever measured a cancer outcome. What the studies measured was a short-term rise in NK cell activity after multi-day forest trips, and that evidence has serious problems covered further down.

The bigger claim: is it the chemicals trees release?

Here is the story you have probably read: trees release invisible compounds called phytoncides to protect themselves from bacteria, fungi, and insects. You breathe them in. They calm your nervous system and boost your immune system. Pick a pine or cedar forest, the story goes, because aromatic evergreens release the most.

Trees do release these compounds, which is why a pine forest smells like a pine forest. The real questions are how much of them reaches you when you are actually standing in a forest, and whether that amount does anything. This is where the popular story runs ahead of the evidence.

The amount in real forest air is tiny

Scientists have measured these compounds in real forests. The main one studied is alpha-pinene, the sharp piney-smelling compound. Field measurements across many forests find it usually sits between about 1 and 13 micrograms per cubic metre of air, and often below 2.

Now compare that to the studies that found an effect from the compound. The best-known one is Falk and colleagues, published in 1990, which had volunteers breathe alpha-pinene in a sealed chamber. The lowest dose they used was 10 milligrams per cubic metre. That is 10,000 micrograms, roughly a thousand times more than a forest gives you.

So real forest air carries hundreds to thousands of times less of this compound than any study that found an effect. That does not prove forest levels are too weak to matter, because no one has tested the tiny forest-level dose directly to find out. But it does mean the whole "healing chemicals" story rests on doses you never actually breathe in the woods.

When scientists test the compound directly, the results clash

Two careful studies gave people the isolated compound and got opposite answers. A 2016 Japanese study had people breathe vaporized alpha-pinene and found it slowed their heart rate and shifted their nervous system toward its calming mode. A stricter 2025 Johns Hopkins study, better designed so neither the subjects nor the researchers knew who got what, had 19 adults breathe the same compound and found no effect at all on mood, thinking, or vital signs.

One says calming, one says nothing. That is genuine uncertainty, not a clear yes or no.

The strongest real-world test

The cleverest experiment yet came from the University of Washington in 2025, published by Levy and colleagues. Forty-three people sat in the same forest twice, wearing air-purifying helmets. In one session the helmet let the tree compounds through. In the other, a charcoal filter stripped them out. Nobody knew which was which. Everything else, the same trees, the same quiet, the same view, stayed identical. The only thing that changed was whether they were breathing the chemicals.

The main measurement, a marker of nervous-system calm, showed no difference. That is a real blow to the idea that the compounds are what makes forest bathing work. But it was not a clean zero. Two markers of inflammation in the blood, called IL-6 and TNF-alpha, came out lower in the sessions where people breathed the tree compounds, and a stress measure based on sweat response shifted the same way. So the compounds may do something small to the body, just not the big calming effect the popular story promises.

Does any of it get into your body?

A small Japanese study found the compound did rise in people's blood after an hour of forest walking, though the amount stayed extremely low. A larger study in a Mediterranean oak forest found no clear rise across the group. And a 2025 study using a more sensitive urine test found that after four hours in a green space, breakdown products of the compound did show up in people's urine. So your body does absorb a trace of it. Whether that trace matters is the part no one can answer.

The Japanese immune-cell studies

The NK cell findings come almost entirely from one lab: a group led by Qing Li at Nippon Medical School in Tokyo. Across several small studies using the same 12 or 13 people, they reported higher NK cell activity after multi-day forest trips.

There is a simple problem. Most of these studies compared a weekend forest trip against a normal work day. A forest trip means hours of walking, time off, better sleep, and a change of scenery, all at once. And it is well established that exercise alone raises NK cell activity. So the boost could easily come from the walking and the vacation, not the trees.

The strongest study in the set, from 2008, tried to fix this by comparing a forest trip to a city trip with the same amount of walking, and still found the boost only in the forest group. That is the one real piece of evidence that it is not just exercise. But it is a single small study. Two other labs, one in Taiwan and one studying a bamboo forest in China, found something similar, but both were small and neither directly repeated the original. The immune finding is interesting and mostly unconfirmed.

Does the type of forest matter?

Short answer: no one knows, so do not choose a forest for its trees.

Different trees release different compounds, and some release more than others. But since no one has shown these compounds produce a health benefit at forest-level doses, there is no basis for saying a pine forest is healthier than an oak forest, or a redwood better than a cedar. A few facts about tree chemistry are worth knowing anyway, because they show how shaky the "pick the right tree" advice really is.

What a tree contains is not what it releases. Ponderosa pine is the clearest example. Crush its needles and the oil looks rich in pine compounds. But measure the actual air around a living ponderosa on a summer day and it is dominated by a completely different compound. The smell in a bottle of pine oil is not the air you breathe on the trail.

Most American trees have barely been measured. Only a few, like Douglas-fir and ponderosa pine, have solid field data on what they actually put into the air. Others often named in forest bathing guides, including giant sequoia, eastern hemlock, and bald cypress, have almost none. The numbers you see quoted for them are often computer estimates, not real measurements.

The Japanese "cedar" everyone copies is a different tree. Much of the original research used hinoki, a Japanese cypress. American writers reach for western red cedar as the local stand-in because it is also in the cypress family. But its chemistry is dominated by a compound in a completely different class from the ones in the Japanese studies. It is not the same tree in a bottle, and even hinoki's own chemistry varies wildly from study to study. There is no fixed target to match American trees against.

What actually holds up

Take away the shaky chemistry, and you are not left with nothing. You are left with a few plain reasons a forest is a good place to spend two hours.

A forest is quieter and cleaner than a city

This one needs no forest bathing study at all. Forests have less air pollution and less noise than a street. And the link between lower pollution, lower noise, and better heart and lung health rests on a huge body of evidence, far stronger than anything in the forest bathing research. If you want the most solid reason to spend two hours under trees instead of beside a road, this is it.

Deeper into the forest, the air changes slightly

This is the one place tree chemistry actually affects a decision, and several field studies agree on it. The tree compounds are more concentrated inside a stand of trees than at its edge or in a clearing. Older, denser forest has more than young forest. And living forest has more than dead forest.

That last point is worth explaining, because it surprises people. Whole stretches of American forest are standing dead, killed by bark beetles or diseases like the insect that has wiped out many eastern hemlocks. A dead tree stops releasing these compounds, because the living needles have to be alive and active to produce them. A Czech study measured healthy forest putting out clearly more of the compound than a nearby beetle-killed stand that was close to zero.

The practical takeaway is not that walking deeper heals you more. The amounts involved are tiny either way. It is simply that the edge of a forest is also where the road, the parking lot, and the noise are. Walking in gets you away from all of that, which is the real benefit.

The other explanations are interesting but unproven

If it is not the chemicals, maybe it is the quiet, the birdsong, the green scenery, or contact with harmless soil microbes. Each of these has some research behind it, and none of it is settled. Studies on nature and attention lean positive but are small and have failed to repeat cleanly. Birdsong studies are split. The microbe idea is fascinating in theory but barely tested for a short forest walk.

So the honest position is that we do not know exactly why forest bathing seems to help. Quiet, shade, and a slow walk are good enough reasons to go without pretending any one of them is the proven mechanism.

The bottom line

Forest bathing is worth doing. It just is not worth doing for the reason most guides give.

The evidence says time in a forest probably lowers stress a little, though the proof is thin. The claim that healing tree compounds are behind it does not hold up, because you breathe in far too little of them to match any study that found an effect, and the direct tests of those compounds have come back split or empty. Nobody can honestly tell you that one tree or one forest is healthier than another.

So choose a forest the way you would choose anywhere you want to sit quietly for two hours. Look for shade, gentle ground, low noise, clean air, and somewhere to sit. Walk in far enough that you cannot hear the parking lot. Stay long enough that you stop checking the time.

And a closer forest you visit often beats a famous one you reach once. Showing up regularly tends to matter more than picking the perfect spot, and a walk in the woods is no different.

Frequently asked questions

What are the best U.S. forests for forest bathing?

Our top picks for the best U.S. forests for forest bathing are Redwood National and State Parks, Humboldt Redwoods, and Olympic National Park, followed by Congaree and the old-growth cedar of the Idaho Panhandle. This is an editorial ranking of places that suit a slow, unhurried visit, not a measurement of health effects, since no study has compared these forests head to head.

What trees release the most phytoncides?

No universal ranking exists. Phytoncides cover many different chemicals, and what a tree releases changes with temperature, sunlight, season, moisture, and damage. Aromatic conifers such as cypress, cedar, pine, spruce, fir, hemlock, Douglas-fir, redwood, and sequoia have the highest monoterpene content in their oils. The more useful point is that no one has shown these compounds reach you at a meaningful dose in a real forest, so the ranking barely matters when you are choosing where to go. Pick for shade, quiet, and how long you can stay.

Do tree chemicals actually explain forest bathing?

Not on the current evidence, though the idea is unproven rather than ruled out. Real forest air carries far less of these compounds than the amount used in studies that found an effect, and that tiny forest-level dose has barely been tested. When scientists gave people the isolated compound directly, one study found a calming effect and a stricter one found nothing. The best real-world test, which filtered the compounds out of forest air to see if it mattered, found no change in the main measurement. Forest bathing may still help, and if it does, the quiet, the walking, and the cleaner air are at least as good an explanation as the compounds.

Are pine trees best for forest bathing?

Pine resin is rich in the monoterpenes the research focused on, so pine looks like the obvious pick on paper. In practice the concentration in the air is too low for that to clearly matter, and one careful study of ponderosa pine found its actual daytime emissions were dominated by different compounds than its needle oil would suggest. Choose a pine forest because you like pine forests, not because of what it releases.

Do American trees release the same compounds as Japanese hinoki?

Some overlap, but the match is looser than usually claimed. Douglas-fir is the closest, with alpha-pinene, beta-pinene, and 3-carene making up roughly 95 percent of its emissions. Western red cedar is often called a hinoki relative because both are in the cypress family, but it is dominated by thujone, a different compound class. Eastern hemlock is dominated by an ester rather than a monoterpene. And hinoki itself ranges from about 1 percent to 66 percent alpha-pinene across studies, so there is no fixed profile to match against.

Does forest bathing increase natural killer cells?

Small Japanese studies reported higher natural killer cell activity after multi-day forest trips. The strongest of them compared a forest trip against a city trip matched for physical activity, alcohol, and sleep, and found the increase only in the forest group. Most of the others had no control group and compared a weekend trip against an ordinary workday, which does not separate the forest from the walking and the time off. Nearly all the work comes from one lab using the same twelve to thirteen participants, with weak partial support from two independent groups. It is a real signal with thin replication, not an established fact, and it does not show that forest bathing prevents disease.

How long do forest bathing effects last?

The widely repeated 30-day figure comes from one small 2008 study in which participants took multi-day trips to Japanese forest parks and walked for hours each day, and whose raised natural killer cell activity was reported to still be measurable more than 30 days later. Treat it as a single, unreplicated finding tied to a specific multi-day protocol, not a rule. It should not be applied to a single afternoon walk, and as covered above, the whole immune-cell line of research remains weakly supported.

How long should a forest bathing session last?

There is no validated dose. Sixty to 120 unhurried minutes is a practical starting point and matches the length used in several studies, but it is a guideline rather than a prescription. A shorter session you repeat every week is worth more than a long one you do once a year.

Does it matter how far into the forest I walk?

For the air, slightly. Measurements consistently show higher concentrations of tree compounds inside a stand than at the edge or in a clearing, and higher in older, denser forest than in young forest. Nobody has published the distance at which it plateaus. For everything else it matters more, because the edge of a forest is where the road noise, the parking lot, and the other people are, so getting away from the edge is worth it regardless of the chemistry.

Is a city park good enough for forest bathing?

For sensory immersion and stress, yes, if it is quiet, well shaded, and away from heavy traffic. Given how weak the chemical case turns out to be, the tree species in a city park matter less than most people assume. A quiet park you visit weekly is worth more than a famous forest you visit once.

Is a hardwood forest useful for forest bathing?

Yes. The conifer chemistry argument is the weakest part of the whole subject, so a hardwood forest gives up very little. Shade, quiet, natural sound, cooler temperatures, and visual depth are all present regardless of species, and some of the best forest bathing locations in the United States, including Congaree, are hardwood or mixed forests.

Is forest bathing the same as hiking?

No. Hiking is organized around distance, elevation, or reaching a destination. Forest bathing is organized around slowing down and paying attention with your senses. The two often use the same trails, but the goal is different: you are there to be in the forest, not to get anywhere.

Can forest bathing prevent cancer?

No. No evidence supports using forest bathing to prevent or treat cancer. The natural killer cell findings get stretched into cancer claims regularly, but those studies measured immune markers in small groups over short periods and did not measure cancer outcomes in anyone.

Are essential oils the same as visiting a forest?

No, and the comparison cuts in an unexpected direction. Diffusing concentrated oil in a closed room actually delivers a far higher dose of these compounds than standing in a forest does. What an oil cannot give you is the quiet, the light, the temperature, the sound, the walking, and the space, which are the parts with better evidence behind them.