The Bighorn River flows through much of north-central Wyoming and southern Montana, cutting through the rugged and angular terrain of the Bighorn Basin. Red rocks and complex geology are distinctive features of this physiographic region. The semi-arid climate creates a sparsely vegetated environment where dramatic geologic structures are easily identified from space and from the ground.

An astronaut onboard the International Space Station (ISS) looked westward to take this photo, capturing the shadows from the local sunrise. Along the right side of this image, the Bighorn River is almost hidden amid the mountains due to the shadows cast into Sheep Canyon.

Located in Wyoming's Rocky Mountains, Bighorn Basin is a large, oval-shaped depression and home to many rivers and geologic formations. This photo is centered on the Sheep Mountain anticline, a type of fold that forms due to compressional stress on rock layers. Geologic structures like this anticline are found throughout the Bighorn Basin and many are associated with oil and gas reservoirs.