A purple fence post is meant to send a message to anyone who comes across it, and that message is: No trespassing!

While property owners have the option of hanging a sign to indicate private property, signs can deteriorate over time while paint will last a lot longer and still convey the same message.

However, while some states use different color paint – Idaho and Montana use orange paint – the idea is the same.

In order to comply with the law, the purple stripe must be 3′ to 5′ off the ground and at least 8″ long and 1″ wide. The markings must not be more than 100′ apart.