Abstract: A sign post is comprised of two principal components, namely a lower tubular member and an upper tubular member which is telescoped over the lower member. The lower member has ground penetrating members at its lower end. A striker plate in an upper region of the upper member is adapted to strike an anvil plate closed upper end of the lower member when the upper member is reciprocated on the lower member to drive the ground penetrating members into the ground. A pin arrangement permits the upper member to be locked in different positions on the lower member.