The Trouble with “Natural”: Why That Word Is Failing Us in the Mountains

Last week a comment thread on one of my trail-maintenance posts got philosophical fast. It started simply enough — someone named Brent wrote: "So... the trails are more natural... and that's a problem?" Another reader, Tommy, replied: "Are trails natural or unnatural?" Then a third commenter, Steve, jumped in arguing that human trails should form on their own, the way game trails do — that it's natural for hikers to walk and unnatural for trail crews to intervene with shovels and switchbacks.

I've watched this same argument play out a hundred times, on a hundred different outdoor topics. And every time, the word natural is doing more harm than good. It generates heat instead of light. It lets us argue past each other while the actual problems — and the actual solutions — go untouched.

Here's the context for that particular argument, in numbers. The Colorado Fourteeners Initiative estimated about 265,000 hiker use days on Colorado's 58 highest peaks in 2024. Mount Bierstadt and Quandary Peak each saw something in the range of 26,500 to 28,000 hikers in a single four-month season. The 12 closest 14ers to Denver accounted for roughly 54% of all that visitation. We're not talking about lonely game trails through low-traffic backcountry. We're talking about some of the most heavily used alpine routes in the United States.

So when someone says "let trails form naturally" on a 14er, they're not really making a philosophical observation. They're making a policy proposal — and the policy needs to be evaluated against what would actually happen. To do that honestly, we have to talk about what natural actually means.

Two Definitions, Pointing in Opposite Directions

In most everyday use, "natural" is shorthand for the opposite of human design. To be natural is to be of nature — and to not be of human making. By that definition, all trails are unnatural. So is every campground, sign, switchback, and water bar in every wilderness area in the country.

But humans have walked established paths for tens of thousands of years. We've worn footways into the dirt of every continent we've inhabited. From that angle, walking on trails isn't just natural to us — it's one of the most ancient and characteristically human things we do. The American Romantic tradition (Emerson, Thoreau, Muir) anchored the first definition into our cultural imagination, while archaeology and historical ecology have steadily backed the second.

So the word genuinely points in two directions at once. That's not a small problem. It means whenever someone uses "natural" in a debate, you can't actually be sure which definition they have in mind — and they may not be sure either.

The Real Problem: Smuggling Judgment Into Description

The bigger issue isn't the dual definition. It's that "natural" has stopped being a descriptive word at all. We use it to mean good.

We talk about humans corrupting and degrading nature. But almost no one ever argues that nature corrupts or degrades humanity. That's a strange asymmetry once you notice it. It only makes sense if "natural" already carries a moral charge — if "of nature" is presumed to mean "of value" before the conversation even starts.

Philosophers have a name for this move. It's called the appeal to nature fallacy: the assumption that something is good because it's natural, or bad because it's unnatural. The closely related naturalistic fallacy was named by the philosopher G.E. Moore in his 1903 book Principia Ethica, where he argued that defining "good" by reference to natural properties is a category error. You can't get an "ought" from an "is" by way of the word "natural" — but we try to do it constantly, in arguments about food, medicine, sexuality, and yes, trail maintenance.

I first encountered this kind of thinking in depth as an undergraduate at the University of Wisconsin–Madison, where I had the chance to study environmental history with William Cronon — sitting in his lectures, taking his seminars, and arguing through these ideas with him directly. Cronon's 1995 essay "The Trouble with Wilderness" makes a structurally similar argument about a different word: that wilderness — which we treat as a natural category — is actually a cultural construct, freighted with values and historical baggage that it pretends not to have. Cronon spent years arguing that the way Americans use "wilderness" actively damages our ability to think clearly about the environment, because it separates "nature" from everywhere we actually live. The same critique applies almost word-for-word to natural.

The Pristine Myth

Here's where things get genuinely uncomfortable for the "let nature take its course" position.

Even the picture we have in our heads of a "natural" American landscape — pre-Columbian forests, prairies, and meadows untouched by human hands — turns out to be a story we tell ourselves. The archaeological and paleoecological evidence is increasingly clear that indigenous peoples actively shaped most of the North American landscape for thousands of years before European contact. Fire was the primary tool. Native peoples burned to clear undergrowth, drive game, maintain prairies and oak savannas, encourage food plants, reduce wildfire fuel loads, and keep travel corridors open. The U.S. National Park Service now openly acknowledges this, and peer-reviewed research from sites like Jemez Pueblo in New Mexico documents this management going back many centuries.

Yosemite Valley's iconic meadows and oak woodlands were maintained by intentional burning for over 4,000 years. The "untouched wilderness" John Muir described in the Sierra was, in significant part, a managed landscape that briefly went unmanaged after Native peoples were forcibly removed.

Cronon's sharpest observation, in my view, is exactly this: removing indigenous peoples to create "uninhabited wilderness" invented the very pristineness that the wilderness preservation movement later claimed to protect. The pristine wasn't found. It was constructed — partly by erasing the management that had shaped the landscape for millennia.

What this means is that when we say "natural" and mean "untouched by humans," we're often describing something that may never have existed in most of North America. The thing we now call wild was, in many cases, the product of long human stewardship.

Where the Moral Usage Falls Apart

Once you see "natural" as a value-loaded word smuggling judgment into description, examples that break the framework start showing up everywhere.

Hurricanes are natural. Tornadoes are natural. They're catastrophes. Disease is natural — bubonic plague was natural, smallpox was natural, malaria still is. We spend millions of dollars extinguishing wildfires triggered by lightning. And what could be more natural than death itself? Yet we spend most of our lives doing everything we can to avoid it.

Outdoor recreation gives us even sharper examples. Avalanches are natural. Hypothermia is natural. Bear maulings are natural. Falling rock is natural. Lightning is natural. Every one of those things is something we work hard to avoid, mitigate, and survive — and no one in the outdoor community would frame avoidance as "fighting nature." We just call it being prepared. The moment you apply "natural = good" to your own gear list, the framework collapses on itself.

The inverse breaks down too. Vaccines are unnatural by any reasonable definition. They're also one of the greatest moral goods humans have ever produced. So are antibiotics, sanitation systems, and the building codes that keep our houses standing in earthquakes. Behavioral-science research on the appeal-to-nature fallacy specifically flags how this thinking drives vaccine hesitancy and other public health failures — because once "natural" gets to mean "good," people who reject medical care can claim moral high ground without engaging with the evidence.

"Natural" can't be doing the moral work we keep asking it to do. It doesn't carry the load. The load needs to be carried by something else.

What to Use Instead: The Vocabulary of Impact

This is where the conversation finally gets useful, because there's already a working framework that does what natural can't.

It's called recreation ecology — an academic discipline that's been studying the environmental consequences of outdoor recreation for over half a century. The field exists precisely because the kind of "natural vs. unnatural" debate we keep having on Facebook is useless to the land managers who actually have to make decisions. Researchers like David Cole, Jeffrey Marion, and Yu-Fai Leung — working through the U.S. Forest Service, the USGS, and universities like Virginia Tech and NC State — have built a different vocabulary, grounded in measurable indicators rather than moral framings.

Instead of asking whether something is natural, recreation ecology asks: what specific impacts is this recreation activity producing, and how do we measure them? The categories include:

• Vegetation cover and trampling damage. CFI cites research showing that as few as 5–10 footsteps on alpine tundra can kill some plants — and recovery rates in the alpine zone are 10 to 1,000 times slower than in the sub-alpine forests just a few hundred feet lower.
• Soil erosion and tread incision. Measured in inches of soil loss per year on heavily used trails.
• Social-trail braiding. Measured in trail-network width and the number of parallel paths through a corridor.
• Wildlife displacement. Measured in altered movement patterns, breeding success, and behavioral indicators like alarm-call frequency.
• Water quality. Measured in nutrient loading, sediment, and pathogens at backcountry water sources.
• Soundscape and night sky impacts. Measured in decibels and lux — both of which affect wildlife and visitor experience alike.

These are objective concepts. We can argue about them, dig into the data, run experiments, change our minds. We can also disagree about which impacts to prioritize — different communities will weight wildlife disturbance against social-trail spread against scenic integrity differently — but at least we'd be disagreeing about something measurable instead of arguing over competing definitions of a single ambiguous word.

Recreation ecology has also produced findings that genuinely change the management conversation. The most counterintuitive is what's called the curvilinear use-impact relationship: the connection between hiker traffic and environmental damage isn't linear. Most damage happens with the first few uses of a corridor. A trail that sees 50 hikers a season suffers nearly as much vegetation loss as one that sees 5,000. Once a path is established, additional traffic does relatively little incremental damage. (Monz, Cole, Leung & Marion 2013, Frontiers in Ecology and the Environment.)

The policy implication is significant: concentrating use on a small number of well-designed, hardened trails is often the lowest-impact strategy, even when those specific trails get crowded. "Crowded but maintained" is frequently lower-impact than "dispersed but eroded." That's the opposite of what an appeal-to-nature framework would predict — and it's exactly why land managers build switchbacks instead of letting hikers find their own way up.

Back to the Trails

So when Steve argued that we should let human trails form naturally — the way game trails do — he wasn't really proposing philosophy. He was proposing a management approach. And we already know what that approach produces at 14er-scale traffic, because we tried it.

The Colorado Fourteeners Initiative was founded in 1994 specifically because the "let nature take its course" approach was producing measurable damage that the alpine tundra couldn't recover from on any human timescale. Hikers were finding their own routes, those routes eroded into gullies, hikers walked around the gullies, and the resulting social-trail networks were eating the very ecosystems people had come to see. CFI now maintains sustainable summit trails on 37 of Colorado's 14ers, and the recreation those trails support generated an estimated $71.9 million in economic impact in 2024 alone.

The fight in the comment thread wasn't really about whether trails are natural. It was about which impacts we choose to manage and which we let run. CFI made that call decades ago, with data — and the decision to actively maintain trails is exactly what allows hundreds of thousands of people to experience the alpine each summer without destroying the thing they came to see.

The Mountains Don't Care What We Call Things

The mountains don't care what we call our impacts. They only respond to how we manage them.

"Natural" was never going to do that work for us. The word points in too many directions, smuggles in too much judgment, and falls apart the moment you press it on real examples. The peaks we love deserve a better vocabulary — one grounded in measurement, in evidence, and in honest accounting of trade-offs. That's the work in front of us. And it's worth doing well, because the next generation of hikers will inherit whatever we choose to do, or not do, with these places.