Substructure in the galactic halo

I review the current observational state of the search for substructure in the Galactic halo within a framework of the different approaches applied to the problem. Generally, such substructure is found whenever it is looked for. Cross-sections of the halo reveal it to be networked with tidal streams. It is likely that at least the outer halo of the Milky Way is predominantly made up of accreted satellites.