Abstract: A nail structure for providing a support surface for subsequent mounting and positioning of elevational rods for utilization particularly in surveying situations. The nail structure includes a first and second spike member orthogonally mounted to a lower or first leg of a generally triangular support truss head when the head is mounted to a main body support, wherein the main body support provides a planar support surface and includes a projection formed at an upper terminal end of the main body support to provide a planar impact head surface for permitting directing of the nail into various structural components such as utility poles. A further improved embodiment of the instant invention includes a benchmark nail structure, wherein a body member is formed with planar body sides for positioning indicator rods utilized in surveying.