These north bound blue hopper cars are transporting black coal along the edges of the Puget Sound below Chuckanut drive in northern Washington. The GATX desgination stands for General American Transportation. The X is a desgination that the railcar is not owned by the railroad and is privately owned. General American Transportation is a railcar leaseing company.
This train is heading north to the Roberts Banks facility in British Columbia Canada, a superport built for the bulk handling of coal. The coal will be exported to China for use in their coal-fired power plants. There are typically two of these long trains a day transporting coal and coke. Coke is a substance generally used in steel manufacturing.