Related Clues:

• Hydroelectric power projects
• Source of strength, figuratively
• Water barriers
• Stokes
• Beavers make them
• Part of GM
• Hoover, etc.
• Broodmares
• Utah's Flaming Gorge et al.
• They're under hoods
• Outboard and electric
• Oil and coal
• Moms on all fours
• Beaver projects
• Man-made lake formers