I had several people ask us about this..... What is a legal fence in Missouri? General fence law "A fence consisting of posts and wire or boards at least 4 feet high which is mutually agreed upon by adjoining landowners or decided upon by the associate circuit court of the county is a lawful fence. All posts shall be set firmly in the ground not more than 12 feet apart with wire or boards securely fastened to such posts and placed at proper distances apart to resist horses, cattle and other similar livestock" (RSMo 272.020). Local option fence law A lawful fence is "a fence with not less than four boards per 4 feet of height; said boards to be spaced no farther apart than twice the width of the boards used fastened in or to substantial posts not more than 12 feet apart with one stay, or a fence of four barbed wires supported by posts not more than 15 feet apart with one stay or 12 feet apart with no stays, or any fence which is at least equivalent to the types of fences described herein" [RSMo 272.210(1)]. "Stays" are vertical supports that are attached to each horizontal wire of a fence. Example of fence required by general fence lawFigure 2. Example of fence required by general fence law. If my neighbor needs a more substantial fence, do I have to pay for it? If a neighboring land- or livestock owner needs a fence above the legal definition, you are required to pay only what your portion of a legal fence would cost. Anything above that cost is your neighbor's responsibility. If my neighbor wants to doze out the old fence and build a new one, but I don't, do I have to allow it? This question brings up two potentially separate issues. First, the tradition in Missouri is that 10 feet on each side of the boundary fence would be cleared before putting in a new fence, but this is not required in the statutes. It is a good idea from a liability standpoint, though (see Liability concerns section). Second, does the current fence meet the legal definition and maintain livestock? If you cannot agree on this, then the associate circuit judge can appoint three disinterested parties to decide.