COLOR SHADED-RELIEF IMAGES OF THE FINAL GRIDDED DATA Color shaded-relief images of the final gridded data at a scale of 1:750,000 are available in two formats for each grid, annotated with tick marks, map scale, and color scale bar. These maps are approximately 32" wide x 46" long if printed. Portable Network Graphics image format file - .png a lossless bitmap image format Portable Document Format image format file - .pdf Adobe-format file file for Adobe* Acrobat readers. * Trade names are used for descriptive purposes only.