Rangers say knock ’em down A field of cairns has been created along the Lower Yosemite Falls Trail. Yosemite National Park said rock-stacking should be left to rangers and trail workers.

Should you leave cairns alone or destroy them? Now, as it turns out, even the National Park Service doesn't have an easy answer. Last week, staff at Yosemite National Park brought the debate over ...

While each park handles cairns differently, the general rule at all parks is to not mess with the rock piles if you come across one. "Don’t knock it down or add to it," the article states.

YOSEMITE NATIONAL PARK, Calif. - Attention, Yosemite visitors! If you see a giant pile of rocks stacked on top of one another - also called cairns - anywhere in the park, go on and knock them down.

"The rock cairns at national parks like El Malpais, Hawai'i Volcanoes, and Acadia are carefully maintained by park staff to keep hikers like you on the correct path," it states. "The cairns at ...