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Leave No Trace

Also called LNT, the seven principles

What is Leave No Trace?

Leave No Trace is a set of seven principles for using the outdoors without degrading it, published by a nonprofit of the same name and adopted by most US land managers. It covers waste, camping, fire, wildlife and how you treat other people.

Leave No Trace at a glance

Principles
Seven
Published by
Leave No Trace Center for Outdoor Ethics
Waste setback
200 ft from water
Also
Law on much federal land

What are the seven principles?

Plan ahead and prepare. Travel and camp on durable surfaces. Dispose of waste properly. Leave what you find. Minimize campfire impacts. Respect wildlife. Be considerate of other visitors. They are deliberately short and deliberately general, because the specifics change with the terrain.

The order is not a ranking, but the first one carries more weight than it looks. Most damage in the backcountry is done by people who arrived without the thing that would have let them do it properly: no trowel, no bag for their rubbish, no way to store food, no idea that fires were banned that week.

Why do land managers care so much?

Because the impact is cumulative and the numbers are large. One person stepping off the trail to avoid a puddle does nothing measurable. A season of people doing it widens the tread by a meter and kills the vegetation holding the soil together, which is why walking straight through the mud is the low-impact choice even though it feels like the destructive one.

The same logic drives the rules that feel most arbitrary. Human waste in a bag rather than a hole, a mandatory canister rather than a hung bag, a fire ban in a place with plenty of dead wood: each is a response to a specific local failure that happened at scale.

Where the principles get specific

Waste is the one with real regional variation. A cat hole 6 to 8 inches deep and 200 feet from water is the general rule, but alpine zones, desert, canyon corridors and heavily used areas increasingly require you to pack it out, and several popular permits now issue you the bag. Check the specific unit rather than assuming.

Food storage is the other. Where a bear canister is required it is a regulation with a fine attached, not a suggestion, and the accepted list is set locally rather than nationally.

What this means when you're choosing

  • The specific land manager's rules, which override the general principle every time
  • Whether human waste must be packed out on the route you are doing
  • Whether fires are banned this week, which changes independently of the season
  • Which food storage containers are accepted, since the list is local

The common mistake

Treating it as a set of opinions

Several of the principles are also law on federal land. Food storage orders, fire restrictions, group size limits and camping setbacks carry citations. Leave No Trace is the ethic that explains the rule, but the rule is the rule.

Common questions

Is Leave No Trace a law?

The principles themselves are an ethic, but several are also enforceable regulations on federal land: food storage orders, fire bans, group size limits and camping setbacks all carry citations. The ethic explains the rule rather than replacing it.

Do I really have to walk through the mud?

Yes. Skirting a wet section is what widens a trail, and a widened trail drains worse, which makes the mud bigger. Boots dry and gaiters exist. The tread does not recover.

Can I bury toilet paper?

In most places you should pack it out even where burying waste itself is allowed, because paper takes far longer to break down and animals dig it up. A growing number of popular areas now require all human waste to be packed out.

Where this is defined

Where this comes up

Guides on Tom's Hiking where leave no trace changes which product is right for you.

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Cat hole

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Switchback

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Cairn

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Blaze

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Scree

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Talus

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Yosemite Decimal System

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Wilderness first aid

Wilderness first aid is first aid adapted for places where help is hours away rather than minutes. It is also the name of the entry-level course, usually 16 hours over two or two and a half days, that teaches patient assessment, improvised care and when someone needs to be evacuated.

DEET

DEET is the most widely used active ingredient in insect repellent, applied to skin to keep mosquitoes and ticks from biting. The U.S. Army developed it in 1946. Its percentage sets how long it lasts, not how well it works, and it can damage some plastics and synthetic fabrics.

Picaridin

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Permethrin

Permethrin is an insecticide you spray on clothing, boots and gear, never on skin, to protect against ticks and mosquitoes. The CDC recommends 0.5 percent permethrin products for tick prevention. A treatment lasts through several washes, and it is dangerous to cats and fish while wet.

Declination

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Lens category

A lens category rates how dark a sunglass lens is, from 0 to 4, by the share of visible light it lets through. Category 3 passes 8 to 18 percent and suits bright trails; category 4 passes 3 to 8 percent, is meant for snow and glaciers, and is unsuitable for driving.

Polarized lens

A polarized lens carries a filter that blocks light vibrating in one direction, which is how glare reflects off water, wet rock, snow and pavement. It makes those surfaces readable instead of a white sheen, but it adds no UV protection on its own.

By Tom · Last reviewed . Back to the glossary