One unique characteristic of the trail marker tree is a horizontal bend several feet off the ground, which makes it visible at greater distances, even in snow.

Native Americans chose trees mainly from the hardwood family in their region. They most commonly shaped oak and maple trees—due to their flexibility when young, and their permanence and ability to retain shape. They bent trees over to form an arch, and secured them to a stake in the ground or tied them to a large stone with a leather strap or vine. They left a new branch to grow skyward from the top of the arch, forming a new trunk. Eventually they removed the old trunk, leaving a knob, a distinctive characteristic of trail marker trees.

Trail trees, trail marker trees, crooked trees, prayer trees, thong trees, or culturally modified trees are hardwood trees throughout North America that Native Americans intentionally shaped with distinctive characteristics that convey that the tree was shaped by human activity rather than deformed by nature or disease. A massive network of constructed pre-Columbian roads and trails have been well documented across the Americas, and in many places remnants can still be found of trails used by hunters and gatherers.