We describe the observations and resultant galaxy cluster catalog from the 2770 deg 2 SPTpol Extended Cluster Survey (SPT-ECS). Clusters are identified via the Sunyaev–Zel’dovich (SZ) effect and confirmed with a combination of archival and targeted follow-up data, making particular use of data from the Dark Energy Survey (DES). With incomplete follow-up we have confirmed as clusters 244 of 266 candidates at a detection significance ξ≥ 5 and an additional 204 systems at 4< ξ< 5. The confirmed sample has a median mass of