The first real town east of Mattawa is Deep River (pop. 4,109), Canada’s first “Atomic Town,” a planned community built for employees of the Chalk River labs just downstream.

Nine miles farther east, you enter Chalk River. In 1945, this tiny logging center became the home of the first atomic reactor outside of the United States. Seven years later, Atomic Energy of Canada, Ltd. (AECL), a government-owned nuclear research organization, was founded here. It designs and sells commercial and research nuclear reactors around the world and produces most of the world’s radioactive isotopes for medical use. In recent years, problems at the Chalk River plant, due to leaks, seismic improvements, and deferred maintenance, caused a serious worldwide shortage of these vital medical products, putting the Chalk River labs in the media spotlight.