If you’ve ever encountered a bent tree while hiking in North American woods, you may have simply happened upon a tree that was bowed by weather, disease or other natural causes. However, you might have stumbled upon an ancient trail marker created by Native Americans hundreds of years ago.

Known as trail trees, these markers were used to designate trails, crossing points on streams, medicinal sites to find plants, and areas of significance like council circles.

“[Native Americans] were very smart and very close to the Earth,” Don Wells, who helps map these trees as part of the Trail Tree Project, told Indian Country Today Media Network. “They could name every plant and know what they could use it for. They knew the trees and could use them to their benefit.”

Centuries ago, these bent trees could be found across the United States, allowing Native Americans to navigate easily across vast distances. While many of these trees remain today, the gaps between them are becoming wider as land is developed, and those that have endured can be difficult to find, as their locations are kept secret to protect them.

How were trail trees created?

When making a trail marker, a Native American would look for a sapling with a trunk about three-fourths of an inch in diameter. The sapling would be bent in the direction that should be followed and then secured in that position by one of several methods.

Sometimes the saplings would be tied down with rawhide, bark or vines, but other times the tiny trees would be weighted down by a rock or a pile of dirt. Once secured, the sapling would be left in this bent shape for a year to lock it in position, at which point, even after it was released, it would continue to grow pointing in the intended direction.

PHOTO BREAK: The world's 10 oldest living trees

While not every tree along a route was bowed, bending hardwood trees at intervals created a continuous route of travel with markers that could be easily distinguished from the surrounding forest.

If there were no available saplings to bend, the lowermost branch of a large tree would be bent to guide travelers, and if the trail entered a non-wooded area, another system of marking had to be used, such as piling stones. However, the use of living trees was the most permanent, and therefore the most often used method, to mark trails.

How did this affect the trees?

While being forced into an unnatural position didn’t kill the trees, it did affect their development.

Having been bent toward the ground, these trees would typically establish a secondary trunk that grew upward and developed branches and leaves. In most cases, the branches of the original trunk would decay and fall off, leaving the original trunk bare.

However, sometimes the bent tree trunk would come in contact with the ground and the tree would develop a second set of roots.

Despite being manipulated by man, the trees would continue to grow, expanding in diameter as they pointed in the direction of the path one should take. To this day, remaining trail trees still point in the same direction they were bent hundreds of years ago.

trail tree created by Native AmericansYears later, this trail tree has a distinctive shape. (Photo: Eddie Lanham/Historical Exploration/Brooks, Georgia)

How can you tell the difference between a trail tree and a naturally deformed tree?

Trees with a bent or bowed shape aren’t rare. Animal depredations could have caused trees to be misshapen, as could weather like wind, lightning, ice and snow.

Falling objects can also pin down a tree, causing it to grow sideways and appear similar to a trail tree. But when this occurs, typically the bend is longer and more subtle, unlike the more clear angle created when man alters a tree’s growing direction.

To the untrained eye, differentiating between a trail tree and one that’s naturally deformed can be difficult — sometimes even for experts.

“The ideal way is to core the tree — find out the age of the tree to determine if it would have been there around the time of the Indians,” said Wells. “But we can’t go all over the country coring trees. Second way is to look for artifacts around the area. We collect as much information as we can, then make the best judgment call.”

Wells, in collaboration with several groups, documents trail trees across the country and maintains their location in the National Trail Trees database. The database includes more than 2,000 trees in 40 U.S. states.

How can you find a trail tree?

Because trail trees aren’t protected by law, the people who map them and study them keep their locations under wraps. The National Trail Trees database is confidential, and while the Trail Tree Project’s website features a map of where these trees have been found, it won’t exactly get you to the tree you want to see.

“All you know is that tree is somewhere within 1,000 square miles in a certain state,” Wells said. “You will never be able to find it from the information that we show.”

To make your odds of seeing a trail tree better, experts recommend hiking in areas where land is less likely to have been disturbed, such as national forest lands, which have long been protected, or mountain community areas that haven’t undergone a lot of development.