The National Park Service is asking visitors to leave the stacks of rocks that are found along hiking routes alone, as messing with them can have detrimental effects for other hikers.
Officially called cairns, the rock piles and help mark where the hiking route in some parks, an article from the National Park Service states. Each park differs on how cairns are used but moving them can mislead visitors who are hiking on the trails.
If you're going to a national park soon and are planning on hiking, here's what you need to know about cairns.
What are rock cairns?
Cairns are stacks of rocks that vary in height and width that help indicate to a hiker where they are by marking the route of the trail. The smallest rock on the very top of the pile is called the pointer stone and helps tell the hiker which way to go.
Rock cairns are also a way to indicate a hiking trail without using a sign or disrupting the authentic nature of the area.
What are the rules for cairns?
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. "Follow the guidelines from theLeave No Trace Center for Outdoor Ethicsto ensure future hikers can navigate the trail and prevent damage to the landscape."
The guidelines advise visitors to not tamper with cairns because if one that was purposefully made is messed with, it may confuse visitors on the correct hiking path. People are not supposed to add to existing cairns, because adding to them could cause them to collapse.
Additionally, the guidelines state that people should not build their own cairns out of the nearby rocks on the trail.
"Moving rocks disturbs the soil and makes the area more prone to erosion. Disturbing rocks also disturbs fragile vegetation and micro ecosystems," the guidelines state.
More park tips:Hiking or camping this summer? What to do if you encounter a bear.
What parks use cairns?
It's important for hikers to check if the park they are going to uses cairns as a directional technique, the article states. Some national parks that use cairns include El Malpais and Carlsbad Cavern in New Mexico, Hawai'i Volcanoes in Hawai'i, and Acadia in Maine.
"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 Acadia National Park in Maine not only guide visitors, but also add some historical interest to the hiking trails."
Some other parks do not use or maintain cairns for directional purposes and tell hikers not to use ones they might see on the trail as a hiking path, such as Utah's Capitol Reef National Park.
"Any rock cairns are ornamental and can often become a problem for hikers who think they are supposed to follow them," the article states.
More on national parks:Which state has the most national parks? Get to know the 63 national parks in the US
Kate Perez covers breaking and trending news for USA TODAY. You can reach her at kperez@gannett.com or on Twitter @katecperez_.
