Related Clues:

• Nickel source
• Mineral bearing rock
• Smelting need
• See 112-Down
• It's refined
• Mineral deposit
• Refinery rocks
• Fuel that's shoveled
• Prospector's discovery
• Forty-niner's find
• Metal deposits
• I-5 state
• Tram cargo, perhaps
• They're mined, I tell ya!
• Type of fuel