The Continental Divide extends from north to south through central New Mexico. The north-central part of the state lies within the Southern Rocky Mountains, and the northwest forms part of the Colorado Plateau. The eastern two-fifths of the state fall on the western fringes of the Great Plains.
Major mountain ranges include the Southern Rockies, the Chuska Mountains in the northwest, and the Caballo, San Andres, San Mateo, Sacramento, and Guadalupe ranges in the south and southwest. The highest point in the state is Wheeler Peak, at 13,161 ft (4,014 m); the lowest point, 2,842 ft (867 m), is at Red Bluff Reservoir.
The Rio Grande traverses New Mexico from north to south and forms a small part of the state's southern border with Texas. Other major rivers include the Pecos, San Juan, Canadian, and Gila. The largest bodies of inland water are the Elephant Butte Reservoir and Conchas Reservoir, both created by dams.
The Carlsbad Caverns, the largest known subterranean labyrinth in the world, penetrate the foothills of the Guadalupes in the southeast. The caverns embrace more than 37 mi (60 km) of connecting chambers and corridors and are famed for their stalactite and stalagmite formations.