Abstract: An adapter for mounting a depth gage onto a mill head of a milling machine is disclosed herein having an elongated mounting bracket with an outwardly projecting block for slidably carrying an indicator rod with spaced apart depth V grooves thereon. The block has a viewing hole for visual observation of the V grooves and an adjustment screw retains the rod at a selected location on the rod. An adjustable anvil is carried on the rod below the markings and has a broad, flat surface cantilevered outwardly beyond the rod and its mounting block so as to receive engagement with the sensing probe of a conventional depth gage mounted on the machine.