If you’re out hiking or strolling through the countryside and spot a fence with purple-painted posts, take note: it’s not just a quirky design choice. That purple paint actually has an important meaning—No Trespassing.

While you might think the color is simply a personal style statement by the landowner, it actually serves a very specific purpose. Purple-painted fence posts are a legal marker used to signify that the property is private and trespassing is not allowed.

Here’s why: “No Trespassing” signs can often get knocked down or become weathered, making them difficult to spot. As a result, many landowners use purple paint to create a clear and visible alternative. In fact, in 16 states, the law specifically recognizes purple paint as equivalent to a traditional “No Trespassing” sign.

Additionally, purple-painted posts are used to warn hunters that hunting is prohibited in that area. This is especially important given the more than 1,000 hunting accidents that happen each year, some of which result in injury or death. To protect families, pets, and animals, landowners use purple paint to prevent accidental harm.

The color itself is known as “No Hunting Purple,” and it’s a color specifically chosen to stand out and make it clear that the area is off-limits.

So, the next time you come across a purple fence post, make sure to turn around and respect the property owner’s wishes—it’s a clear sign to stay away.