Located in Klickitat County, across the Columbia River, the project will use 133 1.5 MW GE turbines.
PPM Energy recently announced the purchase of 500 MW of GE turbines, 300 MW for delivery in 2006 and another 200 MW for delivery in 2007.
Big Horn is expected to be commercially operational in summer 2006.
PPM says it is in advanced discussions to sell the output of the project.