Related Clues:

• Archaeological fragment
• Road material
• Pit goo
• Salt, so to speak
• Roof goo
• It may go on a drive
• Waterproofing material
• Petroleum residue
• Hearth particles
• Andiron residue
• Mount St. Helens residue
• It may hold feathers in place
• It's in the pits
• Kindling, eventually
• Do road work?