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If You Ever Come Across a Rock Cairn, Yosemite National Park Says to Knock It Over

By Margherita Cole on August 5, 2023

Knock Over Rock Cairns at Yosemite National Park

Photo: PantherMediaSeller/Depositphotos

People have used manmade rock stacks—also called rock cairns—since prehistoric times. These markers have served a myriad of purposes, but are usually placed to give directions to travelers and provide protection from the wind. However, while cairns have a long history, their function is currently being misused by many hikers and travelers. That is why Yosemite National Park reminds its visitors to knock over any rock stacks they see.

While some may have mixed feelings about toppling over these towers, there is a good reason to do it. Places like Yosemite aim to maintain their pristine nature without traces of humans, so removing these manmade structures is a necessary part of that.

“Why did Wilderness Restoration Rangers dismantle this rock cairn? According to Leave No Trace ethics when we recreate in wilderness spaces, our goal is to leave no signs of our impact on the land and respect other creatures living in it,” Yosemite National Park says. “Unfortunately, this dramatically oversized cairn is a mark of human impact and is distracting in a wilderness setting. Building rock cairns also disturbs small insects, reptiles, and microorganisms that call the underside home!”

Their message was shared alongside a video of a park ranger pushing over an oversized rock cairn which disturbed the otherwise natural landscape—both visually and ecologically. “When used appropriately, rock cairns are great for navigation, safety, and delineating a new or hard-to-follow trail. In general, rock cairns should only be constructed by rangers and trail workers. Please dismantle and refrain from building rock cairns when you visit Yosemite.”

This is an important reminder to anyone visiting not just Yosemite, but other national parks in the U.S. or around the world.