Rangers at Yosemite National Park have asked hikers not to stack up rocks to create their own cairns, and to dismantle ones made by other park visitors. The National Park Service (NPS) posted the request on Facebook, together with a video of a ranger kicking over a particularly outsized cairn built by members of the public.
"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," the NPS wrote.
