"Fort Union Formation" . . "From 55 to 65 million years ago" . . "Stratigraphic cross section showing upper Paleocene coal-bearing rocks of the Tongue River member of the Fort Union Formation in the Piney Canyon NE and Piney Canyon NW quadrangles, Campbell and Weston counties, southeastern Powder River Basin, Wyoming"@en . . . . . . . . "Charts, diagrams, etc"@en . . . . . "Geological cross-sections"@en . . . . . . . . . . . .