Big Bend West Texas USA 2nd October 1980

The Window & the Chisos Mountains looking west from the lodge in the Chisos Basin at the centre of Big Bend National Park out towards the Chihuahua desert.

The Chisos Mountains are mainly of igneous origin and were erupted and deposited during the Cenozoic. The oldest rocks in the mountains are volcanic ash, mixtures of ash and clay, sandstone, and conglomerates.