Introduction

For much of my backpacking career, I followed the Leave No Trace (LNT) guideline of burying human waste in catholes. Over the last decade, my confidence in catholes as a reliable solution has eroded. This shift has been shaped by two key factors: my own field observations and a growing body of scientific evidence on human waste decomposition in various environments. The result is that I now consider pack-out systems the default in alpine, desert, and other fragile settings. I’ll dive into this topic in more detail during our upcoming livestream, “Leave No Trace: Revisiting Best Practices,” but I’ll summarize some of the key science and best practices here.

Field Observations

The first change came from direct experience. On high routes in the Sierra (CA), the Wind River Range (WY), and the Front Range (Colorado), I began to encounter toilet paper and feces in places that had once felt remote and pristine. These were not popular trails, but rather cross-country routes that required skill and effort to reach (albeit routes that had been heavily publicized on the Internet).

I also experimented with GPS-marked catholes in alpine areas of Montana, Wyoming, and Colorado. When I returned to the same locations several months (and sometimes up to 30 months) later, I found evidence of both human feces and toilet paper in 100% of the catholes. Decomposition occurs painfully slowly in these environments: toilet paper fragments always remained, and fecal material was still recognizable. What I observed in the field was consistent with what the literature reported: soils at high elevations and in arid environments are poor at breaking down organic material. Even Ells and Monz (2011), studying fecal smears in mountain environments, noted “substantial reduction in fecal mass… but extensive reduction in fecal indicator bacteria was observed in only the arid and alpine environments” (Ells & Monz, 2011). None of this bodes well for the long-term health of backcountry soils and water sources.

My Current Practice

Today, I rely on a simple, redundant pack-out system. Toilet paper is always placed in an odor-resistant bag (Smelly Proof). For feces, I use dog-waste bags for pickup, and nest them inside a 5-mil mylar zip bag. My waste bags are then carried in a 3 to 5-liter waterproof roll-top bag stored in the rear pocket of my pack. This keeps it separate from other gear and supplies, providing multiple layers of containment.

This approach gives me flexibility. On multi-day routes that traverse alpine ridges and then descend into forested areas, I pack out waste in sensitive locations. I may transition to catholes only when soils are deep, organic, and have high decomposition potential.

toilet kit for backpacking - odor proof toilet paper storage bag, soap/hand sanitizer, TP, and a bidet cap

Situations Where I Still Use Catholes

I will still dig a cathole under specific conditions:

  • Below treeline
  • In organic-rich soils
  • In remote areas away from established campsites and trails

Even in those settings, toilet paper is packed out. Catholes have become the exception rather than the rule for many locations during my mountain trips now.

Why I Made the Change

My primary motivation is ecological. Studies have demonstrated that cold, dry, inorganic, and shallow soils limit microbial activity, slowing or halting decomposition. Seastedt et al. (2001) reported that alpine tundra decomposition is primarily constrained by low temperatures and moisture, with microbial activity being uniformly low.

Pathogens can persist in these conditions for long periods (Ells & Monz, 2011). Fecal contamination indicators can remain viable for years in cold and dry soils. Recreation ecologist Jeff Marion has described improperly disposed human waste as a “delivery vehicle for disease” (The Guardian, 2025).

In heavily used areas, the problem is less about decomposition rates and more about accumulation. Many catholes in close proximity exceed the soil’s limited capacity to absorb waste, and casual hikers’ limited motivation to find remote areas to distribute their waste. Land managers report that improperly disposed waste is now one of the most pressing management concerns in U.S. wilderness areas (The Guardian, 2025).

As an educator, I also feel a responsibility to model the practices I recommend. It is difficult to influence behavior if I am not already using and testing the systems myself. In addition, as land management agencies require stricter practices among hikers and backpackers, I’d like to be at the forefront of best practices with well-oiled systems for managing and packing waste.

Research and Management Context

Some lines of evidence to consider:

  • Ells & Monz (2011) documented a limited reduction of fecal indicator bacteria in alpine and arid environments (Ells & Monz, 2011).
  • Seastedt et al. (2001) confirmed low microbial activity in tundra soils as a primary constraint on decomposition (Seastedt et al., 2001).
  • The Bureau of Land Management now requires pack-out in many deserts and alpine zones, and nearly every river canyon where soils cannot effectively process waste (BLM, 2025).
  • LNT increasingly emphasizes pack-out as the most appropriate method in fragile and high-use environments (Leave No Trace, 2025).
  • A 2024 study of New Zealand mountaineers reported rising adoption of pack-out, with identity and norms as significant predictors (McIntyre et al., 2024).
  • The U.S. Forest Service now mandates pack-out in areas such as the Holy Cross Wilderness in Colorado’s White River National Forest (PBS, 2025).

Stabilization, Desiccation, and Volume Reduction

For me, pack-out is now the default in alpine, desert, and high-use environments. Catholes remain an option in specific, low-risk environments. Carrying out waste requires negligible weight for short trips, but the benefits in terms of ecological protection and visitor experience seem significant to me, especially in crowded areas.

My current challenge is managing waste effectively during longer trips, where the accumulated weight becomes significant. I’m studying various methods to manage stabilization and odor control, volume reduction, and possibly dessication.

Human feces are composed of approximately 70–80% water. The bulk of what is carried out in a containment system is therefore moisture, not solids. Without treatment, this water contributes to added weight, bulk, and odor during transport.

From a waste management perspective, three strategies are relevant:

  • Stabilization: adding materials (e.g., gelling agents, absorbents, or alkaline powders) that immobilize liquids, reduce odor, and suppress microbial activity. Stabilization improves containment reliability and handling safety, but does not necessarily reduce weight.
  • Desiccation: removing water through evaporation (or possibly absorption into some type of disposable desiccant), which decreases both weight and pathogen survival. In the field, proper drying requires specialized material technology that allows vapor to escape while retaining solids.
  • Volume reduction: compacting or shrinking the overall waste package to reduce what the backpacker carries. Commercial systems achieve this by immobilizing waste in dense gels; experimental systems, on the other hand, employ membranes or heat-assisted drying to drive off water vapor.

Practical Guidance for Backpackers

  1. Prioritize containment over treatment. A durable, leakproof bag system remains the most reliable option. Use a commercial kit (e.g., WAG/Restop) or a DIY multi-layer system with odor- and puncture-resistant bags.
  2. Separate toilet paper from feces. Carry toilet paper in a dedicated odor-resistant bag. This minimizes access to the feces bag, reduces cross-contamination, and makes handling easier.
  3. Use lightweight absorbents sparingly. A small amount of biochar, sawdust, kitty litter, or commercial gelling powder inside the feces bag can absorb free liquid, reduce odor, and modestly reduce volume (by making everything more compressible with less mess). Carry only what is needed for the number of anticipated uses.
  4. Recognize the limits of sealed systems. Standard sealed waste bags (DIY or commercial) will not lose water weight in the field. Evaporation requires a vapor-permeable but liquid-tight liner or a vented system with odor molecule (e.g., carbon) filtration, which are not part of current backpacking kits. Exterior storage may help with odor segregation and convenience, but it does not aid in drying.
  5. Do not expose waste to drying. Leaving feces in the open to air – or to sun-dry – is inconsistent with Leave No Trace principles and creates health risks. Any desiccation efforts must occur within a contained system.
  6. Keep weight expectations realistic. Full desiccation is impractical in the backcountry with current systems. The most achievable goals are stabilization (to make waste easier and safer to carry) and modest volume reduction through absorbents.

Conclusion

Backcountry evidence and scientific research increasingly show that catholes are unreliable in alpine, desert, and heavily used environments, where decomposition is slow and pathogens persist. Based on both field experiments and the literature, I now consider pack-out as a normalized approach, recognizing that catholes are best limited to less arid environments with deep, organic soils below treeline. My current practice emphasizes the use of redundant containment systems, separation of toilet paper, and the limited use of absorbents for stabilization and odor control. While future innovations may make desiccation and volume reduction more practical, the priority for backpackers today is secure containment and responsible disposal. In short, the ethic of minimum-impact camping is shifting toward packing out waste as the standard practice. Stay ahead of the curve so you’ll be ready when land management agencies impose stricter regulations.

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