The Gorham Mountain trail at Acadia National park winds up through a forested mountain slope before bursting out onto the one of the granite-boulder covered summits for which the park is famous. But once you get up there, following the loop back down would be tricky if it weren’t for rock stacks built by Waldron Bates — they feature a long flat rock supported by two legs and a smaller rock pointing in the direction of the trail. For centuries, humans have been building such markers. But many trail aficionados have one thing to say to people building stone piles in the wilderness: Stop.

For High Country News, Robyn Martin writes that there is an annoying plague of rock stacks balanced carefully atop one another in the West.

These piles aren't true cairns, the official term for deliberately stacked rocks. From middle Gaelic, the word means "mound of stones built as a memorial or landmark." There are plenty of those in Celtic territories, that's for sure, as well as in other cultures; indigenous peoples in the United States often used cairns to cover and bury their dead. Those of us who like to hike through wilderness areas are glad to see the occasional cairn, as long as it's indicating the right way to go at critical junctions in the backcountry.

Pointless cairns have been a problem at Acadia, Aislinn Sarnacki writes for Bangor Daily News. Visitors have knocked down the Bates cairns and even built their own. That’s a problem Darren Belskis, supervisory park ranger, told Sarnacki. “They’re very important,” he says. “If you make your own cairn, it leads people in the wrong direction, and it could get people in trouble. So come out and enjoy the cairns, find them all, but please don’t disturb them.”

Other publications have also written about objections to excessive rock cairns. Adventure Journal has a poll on the issue.

Real cairns are all around the world. The word comes from Gaelic for "heap of stones," writes Michael Gaige for AMC Outdoors. He adds that Norse sailors used stones as before there were lighthouses to help them navigate through Norwegian fjords. In Iceland the stone piles are called varda. Stone piles also mark trails in the Tibetan Plateau, the Mongolian steppe and in the Andes. Many still standing today are ancient.

It may be unfair to call the non-trail marking cairns pointless. Stone cairns can be beautiful and a way to connect to people who visit the area afterwards. For HCN, Martin writes that she noticed many appearing in the West after the so-called Harmonic Convergence in 1987, a synchronized meditation event. She thinks that many of the new stone stacks are people’s way of saying "I was here" or hold spiritual significance.

Moving rocks not only runs the risk of misdirecting hikers, it can also be bad for the environment. Martin writes:

Moving rocks increases erosion by exposing the soil underneath, allowing it to wash away and thin soil cover for native plants. Every time a rock is disturbed, an animal loses a potential home, since many insects and mammals burrow under rocks for protection and reproduction.

The comments on the HCN article include people on all sides of the debate. Commenter Peter Juhl writes:

I am an avid stone balancer. I teach classes on the art form and give presentations on it regularly. I published the first widely available guide book on rock and stone balancing. I love this art form and want to see it grow. However, I am very concerned about the practice of leaving stacks of stones littering natural areas. There is a large worldwide community of stone balance artists who share this concern, and who practice a leave-no-trace approach in creating our temporary art. We build our balances, take some photos, and then dismantle. We strive especially to avoid disturbing natural and protected areas.

Martin concludes with a plea to perhaps leave the cairn-building to the experts, practice leaving no trace in the wilderness and say a silent prayer if moved.