For an experimented hiker, stumbling upon staked rocks on the path comes as no surprise. Around the world, piled up stones can be found in the wild. The most common term for them is cairns, coming from Gaelic for heap of stones, but they are also known as “stone johnnies”, stone balancing, tumuli, dolmen or stupa. No matter what you call them, the important thing is that you just admire them and then continue on your way, without making any alterations, no matter how tempting it might be to try building your own.
The cairns date back to Waldron Bates, one of the original pathfinders on Mount Desert Island. In the 1900s, he built some of the trails that we still walk on today.
Acadia Summit Steward coordinator Steph Ley
In a lot of national parks, the cairns are used to mark the path and point both hikers and guided in the right direction. Some have been there for a long time, placed by local cultures, and are now used as landmarks. Others were built specifically when the paths were laid out, instead of arrows or signs. The cairns integrate with the environment and are also aesthetical in the picture.
Navigational stacks have been used by humans for directions for hundreds of years, on the Tibetan Plateau, the Mongolian steppe and on the Inca Trail in the Andes. They helped humans move from one settlement to another before water ran out. “Where I live, in the Maine woods, it’s not hard to make a trail—just walk through the forest and break a few branches as you pass under the pines. But in the desert or in the high arctic, with no grass to stomp or saplings to bend, humans relied on rock stacks”, explains Katy Kelleher in an article for National Geographic.

Regardless of who put them there or for how long they have been marking the way, under no circumstances should the rock formations ever be disturbed, in any way. Knocking them down or building new ones which do not respect the path’s course could lead hikers astray result in serious problems. Furthermore, Kelleher highlights that misplaced cairns can endanger fragile ecosystems, while prying rocks loose from their place in order to build your own stone stack promotes erosion.