Yes seems to be a co-production.
It was filmed in Canada (Ontario).
"When the Canadian government designated Canadian film productions as tax shelters in 1974, there were many other countries who wanted to get in on the act as well. American-Canadian co-productions began to flourish as a direct result of these incentives, just as they had during the 1930s, when England offered favourable treatment to films made in British colonies."
(
http://www.canuxploitation.com/)