The Eastern Michigan Edison Company was formed as a wholly owned subsidiary of Detroit Edison in 1906 to hold its Huron River properties.

Detroit Edison also expanded through acquisitions; in 1905 the company purchased Washtenaw Light and Power Company, Michigan Milling Company, and Ann Arbor Agricultural Company. As a result of these acquisitions, the company owned the Argo, Barton, Geddes, and Superior generating dams on the Huron River. In 1906 Detroit Edison formed a wholly owned subsidiary, Eastern Michigan Edison Company, and transferred all the Huron River companies to it as subsidiaries.