Reading support:
The timeline shows rail shipments in Montana from 2001 to 2009. In 2009, the weight of rail shipments originating in Montana reached the total of about 44.21 million tons. The top commodity by weight originating in Montana was coal. The top commodity is based on the 38 two-digit Standard Transportation Commodity Code groupings and is determined by the tonnage either originating or terminating in the state (including intrastate shipments).