Abstract: A system for mounting a hollow post about a pipe features upper and lower mounting devices vertically spaced along the pipe. The lower mounting device is slidable along the pipe to define a height at which the hollow post sits atop a base of the lower mounting device. The lower mounting device is mountable on the pipe to allow control over the post height with minimal ground surface preparation. The upper mounting device features two members that are engagable in a number of different relative positions to allow relative positioning of the pipe and post, to each of which a respective one of the two members is engaged. In one embodiment, engagement of the members to separate ones of the post and pipe allows adjustment of the post's position relative to the pipe after installation without removal of the post for access to the upper mounting device.