Cerro Castellan is part of the Chisos Mountains where it is set in Big Bend National Park and the Chihuahuan Desert.

The top of the butte is a caprock composed of Burro Mesa Rhyolite which formed 29 million years ago during the Oligocene period.

[7] Any scant precipitation runoff from the peak's slopes drains to the Rio Grande which is 1.5 miles (2.4 km) to the southwest.

Topographic relief is significant as the summit rises over 1,000 feet (305 m) above Ross Maxwell Scenic Drive in one-half mile (0.8 km).

The mountain's toponym was officially adopted on March 15, 1939, by the United States Board on Geographic Names.