Abstract
We describe the latest results and future prospects of the QUEST survey for RR Lyrae stars in the halo of the Milky Way. Because RR Lyrae variables are excellent standard candles, they are very useful tools for finding sub-structures in the halo that may be tidal tails from dwarf galaxies or globular clusters. Also, we show that observations of the RR Lyrae stars in the Sagittarius streams provide constraints on the shape of the dark matter halo of our Galaxy.
