Rock Cairns (U.S. National Park Service)

Conservationists Want You to Stop Building Rock Piles, Smart News

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

Don't Move Rocks! Friends of the Smokies

Rock cairns should not be messed with on trails: National Park Service

See a Rock Cairn? Push It Over, Yosemite National Park Says

See a rock cairn? Push it over, Yosemite National Park says - The Manual

What to Know About Hiking Cairns - The Thousand Miler

Cairn - Wikipedia

Push these over, say rangers at Yosemite National Park

Rock Cairns (U.S. National Park Service)

Rock cairns discouraged by Yosemite National Park officials - NZ Herald

Rangers, walking groups, urge public to stop making rock towers on hiking trails - ABC News

What can cairns teach us about the spiritual journey?

Yosemite says rock cairns are bad — and you should knock them down - Los Angeles Times