Gilsonite is interesting stuff. It was what made Ford Model T paint black. It had numerous other uses, as well. The only significant reserves of it are/were found along the Utah/Colorado border north of Mack--thus the reason for the Uintah's existence, and in South Africa.
The refinery west of Fruita refined gilsonite into gasoline for years after the railroad was gone--"gilsonite" gasoline was sold widely on the Western Slope. You could always tell when you were burning gilsonite gas because it would leave a bright orange residue in your car's tailpipe. I don't know whether or not unleaded fuel was ever refined from gilsonite.