In 1719 the Spanish explorer Antonio Valverde y Cosio named the Sangre de Cristo ("Blood of Christ") mountains after being impressed by the reddish hue of the snowy peaks at sunrise. The Pecos National Monument can be seen here, and the Sangre de Cristo Wilderness protects part of the range.
The Sangre de Cristos are fault block mountains with major fault lines running along both the east and west sides of the mountains and, in places, cutting right through them. The mountains were pushed up about 27 million years ago, pretty much as one big chunk of rock. On the west side is the San Luis Valley with the Rio Grande Rift Zone running down the middle. On the southeast side is the Raton Basin with a quiet but still active volcanic field. On the northeast side are the Wet Mountains and the Front Range, areas of pre-Cambrian rock raised up during the Colorado Orogeny some 1.7 billion years ago. The Blanca Massif is also pre-Cambrian rock while the main body of the Sangres themselves is composed of Permian-Pennsylvanian rock, a mix of igneous intrusions, conglomerates and shale that is only about 250 million years old.
The mountains extend southeast for about 250 mi (400 km) from south-central Colorado to north-central New Mexico. Many of the peaks exceed 14,000 ft (4,300 m); Blanca Peak, at 14,345 ft (4,372 m), is the highest. All of the peaks in New Mexico that exceed 13,000 ft (3,962 m) are found in this range. Tourism and mining are the main economic activities.
The Sangrede Cristo Mountains are the southernmost subrange of the Rocky Mountains.
Unlike the rest of the Sangrede Cristo Mountains, these are volcanic, with conical shapes and prominent dikes radiating outward.
Rounding out the Sangrede Cristo Mountains are the group of peaks near Santa Fe and surrounding the Pecos Wilderness, which protects the source watershed of the Pecos River.