The waters of the Clark Fork River gently flow below, and the occasional celebratory remarks of a fisherman on the rivers edge behind me fill the calm mountain air, until 60 cylinders and 10,800 horsepower of EMD 645 disrupts the tranquil scene, hustling a heavy 119 car manifest out of the siding at Colby. As the train passes, the smell of spent diesel fuel is overtaken by fresh woodchips fills the nostrils, adding to already pleasant display that Mother Nature has to offer.