The SPTpol Extended Cluster Survey (SPT-ECS) is a 2770deg 2 that covers two separate regions of sky with low dust emission that lie north of previous areas surveyed using the South Pole Telescope (SPT): a 2200deg 2 region bounded in right ascension (RA) and decl.(DEC) by 22h<= RA<= 6h and-40< DEC<-20, and a second 570deg 2 region bounded by 10h<= RA<= 14h and-30<= DEC<=-20.