I talked to one of the engineers at the Colstrip, MT plant about 15 years ago. They were running two draglines to dig the coal out of the ground. He told me that the electricity bill was $1 million each / month. That process continues every month until the mine is depleted. Engineer also told me that it was getting harder to mine the coal every year because some mistakes in strategy were made in the early days of the mine. It won't be long until the mine is shuttered and a big reclamation bill will be shuffled on to the taxpayers of Montana. There are already rumblings about how far in deficit, the reclamation bonds are.