If you see green paint on a tree, it won't be by accident. It was painted on for a reason; why it was will largely depend on ...

Whether you're walking along a city sidewalk or hiking deep in the forest, you might occasionally notice paint marks on tree trunks (or even a metal band once in a while). Those paint marks are codes ...

If you spend enough time surrounded by trees, you may come across some that have been marked with various colors of spray paint, using different symbols, letters, or numbers. In most cases, this is a ...

Add Yahoo as a preferred source to see more of our stories on Google. An orange circle painted on a tree in the woods - Mbprojekt_maciej_bledowski/Getty Images It's not unusual to spot markings on ...