Viewpoint going up the eastern side of US Highway 14 over the Bighorn Mountains in Wyoming. Tilted strata of sedimentary rock from the Paleozoic Era (570-245 million years ago, MA) are exposed. Precambrian rock (granite and gneiss) in the Bighorn range bowed upward 60MA due to compression of the crust with sagging of the basins to the east and west. The Paleozoic layers were eroded from top layers and persisted along the slopes.
Road cut sedimentary layers from the Amsden formation (Pennsyvanian period 280-325 MA) composed of thin layers of red shale, limestone, dolomite, sandstone and siltstone deposited from the shallow overlying Western Interior Seaway.
The dip in the strata in the right side of the field is a syncline along a small fault cutting the Amsden formation.
Darby formation from the Devonion period (360-410 MA) composed of predominantly of weathered limestone and dolomite.
Fallen City is a rock slide of Madison formation limestone (349-326 MA) near the highway summit.
Precambrian granite near the top of the mountain highway are from the core of the mountain range.
Highway 14 heading towards the western downward slope. Peaks of Bighorn dolomite (Ordovician - 505-438 MA) are in the distance and are the surviving remnants of the Paleozoic and Mesozoic marine sedimentary rocks.
