Sheep mountain, Wyoming
This amazing image is the result of folded rocks – a plunging anticline and a plunging syncline. An anticline a fold that is convex up and has its oldest beds at its core, while a syncline is a fold with layers younging to the centre of the structure. Anticlines and synclines form when rock layers are compressed, as a result of ductile deformation.
The Sheep Mountain anticline is found between Greybull and Lovell, in Wyoming. The view here is to the southeast and the anticline plunges to the northwest; the syncline is at the left and is northwest-plunging. These formed as a result of east-directed compression 65 million years ago. The Bighorn River has been superimposed across this structure.
Read more (and see more photos): http://www.geology.wisc.edu/~maher/air/air07.htm