Suppose you are a landowner or leaseholder seeking a way to notify deer, turkey, or mushroom hunters, fishermen, UTV joyriders, or folks on a float trip who use your property to disembark. In that case, you may want to post the boundaries of your property to warn any person and prevent them from trespassing.

Under Missouri law, a person commits first-degree trespass (class B misdemeanor) if they knowingly enter the fenced property or where the property owner gave the person a trespass notice. One type of lawful trespass notice is the use of purple paint.

In 1993, the MO. Legislature enacted Section 569.145, informally labeled the “Purple Paint Law.” This statute allows landowners or leaseholders to post the boundaries of their real property by placing an identifying purple mark on trees or posts. If the purple paint is placed as required under the law, such posting shall be found to be reasonably likely to come to the attention of potential intruders for the purpose of establishing first degree trespass.

• To comply with the law, a landowner (or leaseholder) must make sure that each purple mark:
• is a vertical line of at least eight inches (8”) in length;
• shall be no less than three feet (3’) nor more than five feet (5’) off the ground;
• placed no more than one hundred feet (100’) apart; and,
• shall be readily visible to any person approaching the property.
• Alternatively, a landowner can make sure that each purple mark:
• is on a post capped or otherwise marked on its top two inches (2”);
• shall be not less than three (3’), but not more than five feet, six inches (5’ 6”), off the ground;
• shall be no more than thirty-six feet (36’) apart; and,
• shall be readily visible to any person approaching the property.

If the cap/mark is to be visible from both sides of a fence shared by different property owners (or leaseholders), all parties must agree on the decision to post their own property.

The law does not specifically set out a minimum width of the purple mark, but rather states that the mark “shall be readily visible to any person approaching the property.” Thus, the thicker the purple paint on the tree or post, the easier the mark will be noticeable to the possible intruder.

Consider using purple paint on your property to warn possible trespassers. In addition to the benefit of additional liability protection, purple paint tends to be more economical and lasts longer than “no trespassing” signs. This practice will allow you to have some peace of mind that you have notified possible intruders, and those trespassers can be prosecuted according to the law.