Leaving Albuquerque to the north, I-25 curves to the northeast as it approaches Santa Fe. Continuing 'northbound' at Santa Fe, I-25 heads southeast for approximately traveling through the Santa Fe National Forest and crossing Glorieta Pass (elevation ). It turns north again at Blanchard toward Las Vegas. The highway maintains a north and northeast orientation as it leaves New Mexico traversing Raton Pass () and enters Colorado. From Santa Fe to Trinidad, Colorado I-25 approximates part of the route of the Santa Fe Trail. For its entire length in the state, I-25 shares its alignment with US-85, although US-85 is unsigned.