The Sangre de Cristos are fault block mountains with major fault lines running along both the east and west sides of the mountains with minor faults cutting right through them. The mountains were pushed up about 27 million years ago.
The Sangre de Cristo Mountains are one of the longest mountain chains on Earth. They stretch from Poncha Pass, Colorado, in the north to Glorieta Pass, New Mexico, in the south. There are ten peaks over 14,000' high in the range, more than two dozen over 13,000'.