Missouri Trespassing Laws: What You Need to Know

Missouri: Fast Facts on Trespassing

  • Trespass Law Covers: Buildings, Dwellings, Land
  • Crime Class: Misdemeanor, felony if trespassing on nuclear power plant grounds.
  • Fencing Required?: No, but determines schedule of crime if trespass occurs on fenced prop.
  • Signage Required?: No, but determines schedule of crime if trespass occurs against signage
  • Verbal Notice Required?: No.
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Missouri Trespassing Law Overview

Missouri is a state with predominantly common-sense laws on trespassing. The various statutes are contained within their own sections, easy to reference, and easy to understand.

Trespassing in the state is in almost all circumstances a misdemeanor, but is felonious activity if you trespass upon the grounds of a nuclear power plant, or trespass on the grounds of critical infrastructure with the intent to damage, disrupt or destroy the operations of the facility or installation.

Just a little bit of study will give you a fairly comprehensive grasp of Missouri’s trespass laws.

Relevant Missouri State Statutes

  • Section 569.010 Chapter definitions
  • Section 569.140 Trespass in the first degree, penalty
  • Section 569.145 Posting of property against trespassers, purple paint used to mark streets and posts, requirements.
  • Section 569.150 Trespass in the second degree, penalty
  • Section 569.155 Trespass of a school bus, penalty, schools to establish student behavior policy, when
  • Section 569.086 Trespass on a critical infrastructure facility, penalty
  • Section 569.135 Unlawfully entering or defacing a cave or cavern — penalty

Missouri State statutes covering trespassing helpfully include a section of definitions so there is no ambiguity regarding what certain terms mean that are found throughout the chapter, including several that are most relevant to the trespassing statutes.

As always, you should begin with the definitions when researching any laws and never take the meaning of a given word for granted; even minor variations in the meaning of what seems to be an obvious or commonplace word might completely alter the interpretation of a certain passage containing it:

569.010. Chapter definitions.

As used in this chapter the following terms mean:

(1) “Cave or cavern”, any naturally occurring subterranean cavity enterable by a person including, without limitation, a pit, pothole, natural well, grotto, and tunnel, whether or not the opening has a natural entrance;

(2) “Enter unlawfully or remain unlawfully”, a person enters or remains in or upon premises when he or she is not licensed or privileged to do so. A person who, regardless of his or her purpose, enters or remains in or upon premises which are at the time open to the public does so with license and privilege unless he or she defies a lawful order not to enter or remain, personally communicated to him or her by the owner of such premises or by other authorized person. A license or privilege to enter or remain in a building which is only partly open to the public is not a license or privilege to enter or remain in that part of the building which is not open to the public;

(3) “Nuclear power plant”, a power generating facility that produces electricity by means of a nuclear reactor owned by a utility or a consortium utility. Nuclear power plant shall be limited to property within the structure or fenced yard, as defined in section 563.011;

(4) “To tamper”, to interfere with something improperly, to meddle with it, displace it, make unwarranted alterations in its existing condition, or to deprive, temporarily, the owner or possessor of that thing;

(5) “Utility”, an enterprise which provides gas, electric, steam, water, sewage disposal, or communication, video, internet, or voice over internet protocol services, and any common carrier. It may be either publicly or privately owned or operated.


The definitions in this section are very clear and need a little explanation, but take particular note of the definition of cave or cavern since it encompasses man-made openings into underground voids as well as completely naturally occurring openings.

Also note that in the definition of utility that all such facilities listed are covered whether or not they are publicly or privately owned and operated. Later in this chapter there’s an extensive section covering utility installations and critical infrastructure and this will be very relevant.

Now, on to the first section covering the trespassing laws proper, section 569.140 which details Trespass in the first degree and its penalty:

569.140. Trespass in the first degree — penalty.

1. A person commits the offense of trespass in the first degree if he or she knowingly enters unlawfully or knowingly remains unlawfully in a building or inhabitable structure or upon real property.

2. A person does not commit the offense of trespass in the first degree by entering or remaining upon real property unless the real property is fenced or otherwise enclosed in a manner designed to exclude intruders or as to which notice against trespass is given by:

(1) Actual communication to the actor; or

(2) Posting in a manner reasonably likely to come to the attention of intruders.

3. The offense of trespass in the first degree is a class B misdemeanor, unless the victim is intentionally targeted as a law enforcement officer, as defined in section 556.061, or the victim is targeted because he or she is a relative within the second degree of consanguinity or affinity to a law enforcement officer, in which case it is a class A misdemeanor. If the building or real property is part of a nuclear power plant, the offense of trespass in the first degree is a class E felony.


The standards for trespassing in the first degree are pretty simple. If a person enters or remains upon any real property, which includes land and buildings both, that is fenced or otherwise enclosed in a manner to exclude intruders (fence, wall, barricades, locked, etc.), or has posted signage forbidding trespassing, or if the person trespassing has been given specific communication barring them from the property then they are trespassing in the first degree.

This is a Class B misdemeanor unless the victim, meaning the person whose property is trespassed upon, is current law enforcement or the relative of law enforcement.

In that case, the charge is a class A misdemeanor. If you are dumb enough in these times to trespass upon the grounds of a nuclear power plant, you will be facing a Class E felony.

The next section is 569.145 and covers supplementary marking of property against trespassers:

569.145. Posting of property against trespassers, purple paint used to mark streets and posts, requirements.

In addition to the posting of real property as set forth in section 569.140, the owner or lessee of any real property may post the property by placing identifying purple marks on trees or posts around the area to be posted. Each purple mark shall be:

(1) A vertical line of at least eight inches in length and the bottom of the mark shall be no less than three feet nor more than five feet high. Such marks shall be placed no more than one hundred feet apart and shall be readily visible to any person approaching the property; or

(2) A post capped or otherwise marked on at least its top two inches. The bottom of the cap or mark shall be not less than three feet but not more than five feet six inches high. Posts so marked shall be placed not more than thirty-six feet apart and shall be readily visible to any person approaching the property. Prior to applying a cap or mark which is visible from both sides of a fence shared by different property owners or lessees, all such owners or lessees shall concur in the decision to post their own property.

­­Posting in such a manner shall be found to be reasonably likely to come to the attention of intruders for the purposes of section 569.140.


Acceptable marks for denoting a property boundaries and alerting people that no trespassing is permitted are purple marks of the typical variation for the purpose, placed between three and five feet from the ground.

These purple marks must be at least 8 in. in length, and spaced no wider than 100 feet apart along with being reasonably likely to come to the attention of any potential intruders.

An alternate method is the installation of posts with cap tops at least 2 in. in length, and between 3f ft. and 5 ½ ft. high placed no more than 36 feet apart.

Now on to trespass in the second degree:

569.150. Trespass in the second degree — penalty.

1. A person commits trespass in the second degree if he or she enters unlawfully upon real property of another. This is an offense of absolute liability.

2. Trespass in the second degree is an infraction.


This section is about as short as it can get and still get the point across.

Trespass in the second degree is otherwise unlawfully entering upon any real property of another that does not fit in trespass in the first degree, or any of the other special cases, and is an infraction, not even a misdemeanor.

This could be entering upon the unmarked, unbounded lands of another person, or stepping onto the front yard of a residential property without legal permission. A very minor crime, but a crime nonetheless.

Next, trespass on a school bus, the first of the “special case” trespassing statutes:

569.155. Trespass of a school bus, penalty, schools to establish student behavior policy, when.

1. A person commits the offense of trespass of a school bus if he or she knowingly and unlawfully enters any part of or unlawfully operates any school bus.

2. For the purposes of this section, the terms “unlawfully enters” and “unlawfully operates” refer to any entry or operation of a school bus which is not:

(1) Approved of and established in a school district’s written policy on access to school buses; or

(2) Authorized by specific written approval of the school board.

3. In order to preserve the public order, any district which adopts the policies described in subsection 2 of this section shall establish and enforce a student behavior policy for students on school buses.

4. The offense of trespass of a school bus is a class A misdemeanor.


If you are not the operator of or have specific permission to be on board a school bus then you should not enter or remain on a school bus. The end, it is just that simple. Trespassing upon a school bus is a Class A misdemeanor, whether or not it has students on it at the time.

Next we move on to one of the largest sections covering trespassing in the Missouri statutes, this one covering trespass upon a critical infrastructure facility and all attendant penalties. This is a very lengthy, run-on section:

569.086. Trespass on a critical infrastructure facility — penalty.

1. As used in this section, “critical infrastructure facility” means any of the following facilities that are under construction or operational: a petroleum or alumina refinery; critical electric infrastructure, as defined in 18 CFR Section 118.113(c)(3) including, but not limited to, an electrical power generating facility, substation, switching station, electrical control center, or electric power lines and associated equipment infrastructure; a chemical, polymer, or rubber manufacturing facility; a water intake structure, water storage facility, water treatment facility, wastewater treatment plant, wastewater pumping facility, or pump station; a natural gas compressor station; a liquid natural gas terminal or storage facility; a telecommunications central switching office; wireless telecommunications infrastructure, including cell towers, telephone poles and lines, including fiber optic lines; a port, railroad switching yard, railroad tracks, trucking terminal, or other freight transportation facility; a gas processing plant, including a plant used in the processing, treatment, or fractionation of natural gas or natural gas liquids; a transmission facility used by a federally licensed radio or television station; a steelmaking facility that uses an electric arc furnace to make steel; a facility identified and regulated by the United States Department of Homeland Security Chemical Facility Anti-Terrorism Standards (CFATS) program; a dam that is regulated by the state or federal government; a natural gas distribution utility facility including, but not limited to, natural gas distribution and transmission mains and services, pipeline interconnections, a city gate or town border station, metering station, aboveground piping, a regulator station, and a natural gas storage facility; a crude oil or refined products storage and distribution facility including, but not limited to, valve sites, pipeline interconnection, pump station, metering station, below or aboveground pipeline or piping and truck loading or offloading facility, a grain mill or processing facility; a generation, transmission, or distribution system of broadband internet access; or any aboveground portion of an oil, gas, hazardous liquid or chemical pipeline, tank, railroad facility, or other storage facility that is enclosed by a fence, other physical barrier, or is clearly marked with signs prohibiting trespassing, that are obviously designed to exclude intruders.

2. A person commits the offense of trespass on a critical infrastructure facility if he or she purposely trespasses or enters property containing a critical infrastructure facility without the permission of the owner of the property or lawful occupant thereof. The offense of trespass on a critical infrastructure facility is a class B misdemeanor. If it is determined that the intent of the trespasser is to damage, destroy, or tamper with equipment, or impede or inhibit operations of the facility, the person shall be guilty of a class A misdemeanor.

3. A person commits the offense of damage of a critical infrastructure if he or she purposely damages, destroys, or tampers with equipment in a critical infrastructure facility. The offense of damage of a critical infrastructure facility is a class D felony.

4. This section shall not apply to conduct protected under the Constitution of the United States, the Constitution of the state of Missouri, or a state or federal law or rule.


Whew. That is an extremely lengthy list of prohibited places that I will not repeat here just for the sake of being pedantic. Read that list and understand it.

Also understand that if you were to trespass upon any of those grounds for any reason you’ll be charged with a Class B misdemeanor unless it is discovered that your intention for trespassing was to disrupt, impede or otherwise interfere with the operations of any of those facilities you’ll be charged with a Class A misdemeanor.

If you were to actually succeed in deliberately or accidentally damaging or destroying any equipment or operation of these critical infrastructure facilities during your trespass you will also be charged with a Class D Felony, separate from the trespassing charge. If you don’t have any reason to be there stay away!

Lastly, section 569.135 covers unlawful entry of caves or caverns:

569.135. Unlawfully entering or defacing a cave or cavern — penalty.

1. Unless a person has the prior written permission of an owner, officer, lessee, or superintendent of a cave or cavern, such person commits the offense of unlawfully entering or defacing a cave or cavern if he or she:

(1) Willfully or knowingly breaks, breaks off, cracks, carves upon, writes or otherwise marks upon, or in any manner destroys, mutilates, injures, defaces, removes, displaces, mars, or harms the surfaces of any cave or any natural material therein including, without limitation, stalactites, stalagmites, helictites, anthodites, gypsum flowers, or needles, cave pearls, flowstone, draperies, rimstone, spathites, columns or similar crystalline mineral formation, including the host rock thereof; or

(2) Breaks, forces, tampers with, removes, or otherwise disturbs a lock, gate, door or other structure designed to prevent entrance to a cave or cavern. A person violates this subsection whether or not entrance to the cave or cavern is achieved.

2. No additional appropriations may be made for the enforcement of this section.

3. The provisions of this section do not apply to vertical or horizontal underground mining operations.

4. The offense of unlawfully entering or defacing a cave or cavern is a class A misdemeanor.


Entering any cave without the explicit permission of the owner, officer or superintendent of the said cave or cavern and breaking off, carving, defacing or otherwise disturbing, marking or marring in any way any minerals or other substances found within the cave is a crime; unlawfully entering or defacing a cave.

Also, the same charge is leveled against anyone who breaks, forces or otherwise disturbs a lock, gate or any other barrier or barricade intended to prevent entrance to the cave or cavern.

Conclusion

Missouri is a state with common-sense and well-written laws covering trespassing. In almost every instance trespassing upon land or within buildings is a misdemeanor, unless one trespasses upon the grounds of a nuclear power plant or upon critical infrastructure installations that results in damage or disruption of operations.

If you care to read through the pertinent statutes just a couple of times you should walk away with a pretty good grasp of what the law covers when it comes to trespassing.

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