WREGIS is meant for use in the region covered by the Western Interconnection. This region consists of all or part of 14 states, 2 Canadian Provinces, and Baja California. The 14 states in the region are: Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming.  The 2 Canadian provinces in the region are Alberta and British Columbia.