The full text on the front of this postcard reads: "Mallet Compound Engine. Largest and most powerful in the world used by Southern Pacific Co. on Sierra-Grades, Ogden route".  This postcard scene depicts green grass in the foreground and the giant black steam locomotive in the background.  Also in the background is a building on the left and blue sky above.  The postcard is identified as 2112.  This postcard contains no legend, has no writing, is free of noticeable stains or marks and is in overall very good condition with slight wear on all four corners.