Texas Local Government Code - LOC GOV'T § 72.003. Boundary Markers

(a) The initial corners of the survey shall be designated by boundary markers.

(b) Only a post, a stone monument, or a mound may be used as a boundary marker.

(c) A post used as a boundary marker must be of hewn cedar, cypress, or bois d'arc. The post must be at least eight inches in diameter and at least five feet in length and must be set in the ground to a depth of at least three feet.

(d) A mound used as a boundary marker must be composed of stone if the use of stone is practicable. If the use of stone is not practicable, a mound may be composed of earth. A mound must be at least two feet in height.