SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/hike-cairns-leave-alone

You find a rock cairn beside the trail. What does the Park Service say to do?

Leave it alone. Do not knock it down, add to it or build your own.

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  1. Leave it exactly as it is ✔
  2. Add a rock for good luck
  3. Knock it down to protect nature

Why: Cairns are rock piles that often mark routes. Moving or building them can send later hikers the wrong way, and moving rocks causes erosion.

Huh, didn't know that: Some parks maintain cairns as trail markers, while others, like Capitol Reef, do not, so check the park's trail info first.

The dad joke
Why did the cairn never get lost? It always had a solid foundation.
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References

Answer: Leave it exactly as it is. Cairns are rock piles that often mark routes. Moving or building them can send later hikers the wrong way, and moving rocks causes erosion.

  1. NPS: Rock Cairns www.nps.gov/articles/rockcairns.htm
    If you come across a cairn, do not disturb it.
    Checked 2026-10-12.
  2. NPS: I Didn't Know That! Rock Cairns www.nps.gov/articles/000/idkt_rockcairns.htm
    Moving rocks disturbs the soil and makes the area more prone to erosion.
    Checked 2026-10-12.

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That's stuff everyone should know.