Big Bend National Park - Geography and Climate

Geography and Climate

The park exhibits dramatic contrasts; its climate may be characterized as one of extremes. Dry and hot late spring and summer days often exceed 100 °F (38 °C) in the lower elevations. Winters are normally mild throughout the park, but sub-freezing temperatures occasionally occur. Because of the range in altitude from approximately 1,800 feet (550 m) along the river to Emory Peak in the Chisos Mountains at 7,832 feet (2,387 m) a wide variation in available moisture and in temperature exists throughout the park. These variations contribute to an exceptional diversity in plant and animal habitats. Some species in the park, such as the Chisos Oak (Quercus gravesii), are found nowhere else in the United States.

The 118 miles (190 km) of river that form the southern park boundary include the spectacular canyons of Santa Elena, Mariscal, and Boquillas. The Rio Grande, meandering through this portion of the Chihuahuan Desert, has cut deep canyons with nearly vertical walls through three uplifts made primarily of limestone. Throughout the open desert areas, the highly productive Rio Grande riparian zone includes numerous plant and animal species and significant cultural resources. The vegetative belt extends into the desert along creeks and arroyos.

South of the border lie the Mexican states of Chihuahua and Coahuila and the new protected areas for flora and fauna, which are regions known as the Maderas del Carmen and the Cañón de Santa Elena.