A marked point established in connexion with a triangulation (or traverse) station to provide a starting azimuth for dependent surveys. The geodetic azimuth from the station to the azimuth mark is determined instrumentally; its distance is often determined only approximately but should be accurate enough that the effect, on measured angles, of the ordinary errors made in horizontal control of the USA. These markers are usually located so they are readily available, without special construction to elevate either instrument or centering instrument and target, can be ignored. Since 1928, azimuth markers consisting of bronze tablets set in concrete or stone have been established in connexion with the basic target. At a station having an established azimuth mark, both the geodetic azimuth and the grid azimuth of the mark on the State Plane Coordinate System have been computed and published.