electricity has played an important role in the economic and social development of ontario cities, and port arthur and fort william located at the head of the great lakes are no exception to this rule. industrial development depended on an adequate electric power supply, especially for the pulp and paper industry, the industrial mainstay at the lakehead. safety in the city streets and a high quality of life for the citizens were also provided by electric lighting and numerous electric appliances. there are few households or businesses today that do not have access to electrical power; in this way, it has touched each of our lives. this paper examines the history of the prime provider of electric power at the lakehead, thunder bay hydro and its predecessors. for one hundred and ten years this area has been served by the hydro electric commissions of the two cities. for the first four decades of their existence, roughly 1910 until the end of the great depression, the port arthur public utilities commission and the fort william hydro-electric commission were influenced greatly by the inter-city rivalry. the two cites are geographically isolated from other cities but in close proximity to each other and this set the stage for their rivalry. they competed for such things as industries and electric power. after the great depression began, however this rivalry subsided, where electric power matters were concerned.