Please answer a question about the following article about Chihuahua (state):

The climate in the state depends mainly in the elevation of the terrain. According to Köppen climate classification the state has five major climate zones. The Sierra Madre Occidental dominates the western part of the state; there are two main climates in this area: Subtropical Highland (Cfb) and Humid Subtropical (Cwa). There are some microclimates in the state due to the varying topology mostly found in the western side of the state. The two best known microclimates are: Tropical savanna climate (Aw) in deep canyons located in the extreme southern part of the state; Continental Mediterranean climate (Dsb) in the extremely high elevations of the Sierra Madre Occidental. Satellite image to the right shows the vegetation is much greener in the west because of the cooler temperatures and larger amounts of precipitation as compared to the rest of the state.

Which mountain range dominates the western part of the state?
The Sierra Madre Occidental