In the days of the Canadian frontier, indigenous peoples and fur traders used liquid bitumen to seal their canoes.
With the advance of technology, however, the substance has become a lucrative boon for the oil industry. For the rest of us, it has all the makings of an ecological horror story. Bitumen is a viscous, low-grade petroleum. It is the chief ingredient in the dirty oil mix now being exported from the Alberta tar sands to the United States.