Notes:

This feature class/shapefile represents electric power Independent System Operators. Independent System Operators were set up by the Federal Energy Regulatory Commission (FERC) to provide non-discriminatory access to power and to more adequately administer the transmission grid on a regional basis throughout North America. The following updates have been made since the previous release updated attribution using best available sources.This feature class/shapefile is for the Homeland Infrastructure Foundation Level Database (HIFLD) https://gii.dhs.gov/HIFLD as well as the Energy modelling and simulation community.Data source Oak Ridge National Laboratory.Data and details are hosted by HIFLD as received from the data provider. For questions /feedback, please email hifld@hq.dhs.gov Oak Ridge National Laboratory (ORNL), Los Alamos National Laboratory (LANL), Idaho National Laboratory (INL), National Geospatial-Intelligence Agency (NGA) Homeland Security Infrastructure Program (HSIP) Team