Those are cool and like the other poster, reminded me of Travels with Charlie.
Here's one I found near camp on a deer hunt in AZ a few years back. No telling what it had been used for. Diesel for a logging operation or road crew? Water? ................... Milk!
(Jeez, I had no idea that pic was so blurry. Probably the camera, it could not have been me shaking, it was below freezing that morning)
and look what's still under it:
It's still up there, about 30 miles south of Flagstaff, near the little pine that was rubbed by a buck.
Geno