Rock Cairns (U.S. National Park Service)

Cairn - Wikipedia

Rock cairns discouraged by Yosemite National Park officials - NZ Herald

Please don't stack rocks on your next hike. Here's why. - Lonely Planet

Stop the rock-stacking — High Country News – Know the West

I Didn't Know That!: Rock Cairns (U.S. National Park Service)

The cairns of Acadia: Objects of wonder, subjects of vandals

Resist the urge to build or topple rock cairns - Upworthy

Rock Cairns (U.S. National Park Service)

The cairns of Acadia: Objects of wonder, subjects of vandals

What are Rock Cairns & Why You Shouldn't Build Them – Bearfoot Theory

Quit building giant rock cairns, say Yosemite Park Rangers

Zion National Park - Rock stacking in national parks may seem harmless, or even fun to make, but we invite you to reconsider the problem they pose from a broader perspective. On

STOP BUILDING CAIRNS Ecology for the Masses