[By] Federal Power Commission, Bureau of Power. "Based on information to June 30, 1970." Includes "Key map," and insets, "Plant list," and "Ownership list." 1. Northeastern region.--2. Great Lakes region.--3. North central region.--4. Northwestern region.--5. Southwestern region.--6. South central region.--7. Southeastern region.--8. Alaska, Hawaii, Puerto Rico and the Virgin Islands.