Powerlines in the western United States and Canada as identified by the 22 source data layers used to compile this shapefile. Source data were collected by personal contact or through the internet in the winter and spring of 2004 and assimilated using ArcGIS. This file is a complete record of overhead powerline data that was available as of 5/15/2004 but IS NOT INTENDED TO BE A COMPLETE REPRESENTATION OF THE SUM TOTAL OF ALL POWERLINES ON THE GROUND. These data primarily depict the higher voltage, long distance transmission lines but some arcs likely represent lower voltage distribution lines.