Metasurfaces have unusual abilities to manipulate light with artificial metal nanostructures that are patterned on surfaces of different media. Limited by nanofabrication difficulties, most reported works have been based on 2D metal structures. We have developed an advanced e-beam process that allowed for the deposition of 3D nanostructures which called vertical split-ring resonators (VSRRs). VSRR opens another degree of freedom in the metasurface design. Here we explore the functionality of beam steering with phase modulation by tuning only the vertical dimension of the VSRRs and show that anomalous steering reflection of a wide range of angles can be accomplished with high extinction ratio using the finite-difference-time-domain simulation. We also demonstrate that metasurfaces made of 3D VSRRs can be made with roughly half of the footprint compared to that of 2D nano-rods, enabling high density integration of metal nanostructures.