The Shepherds Flat Wind Farm is an 845 megawatt (MW) wind farm in the U.S. state of Oregon. The facility is located in Eastern Oregon in both Morrow and Gilliam counties, near Arlington. Approved in 2008 by state regulators, groundbreaking came in 2009. The wind farm was built by Caithness Energy using General Electric (GE) 2.5 MW wind turbines, and it supplies electricity to Southern California Edison. The wind farm is estimated to have an economic impact of $16 million annually for Oregon. It is one of the largest land-based wind farms in the world. It officially opened in September 2012.