Day 5 : Stop 2

DAY 5 (9/30/2025) - STOP 2

"Tunnel Vista Observational Site - Lincoln National Forest"

COORDINATES: 32.94624° N, 105.86038° W

Fig. 38 Landscape View From Overlook

    Our stop at the Tunnel Vista overlook (fig. 38) in the Lincoln National Forest placed us along the western margin of the Sacramento Mountains. As we observed, the basin floor lies below the crest of the range because this entire region was stretched and thinned during past episodes of crustal extension. As the western and eastern portions of the crust slowly pulled apart, magma rose through deep fractures, producing volcanic activity that has long since ceased. This process was linked to the development of the Rio Grande Rift, creating a strong elevation contrast between the uplifted block of the Sacramento Mountains and the down-dropped basin to the west. Today, the remains exist as a large structural depression that became the Tularosa Basin and as the corresponding uplifted block that supports the Sacramento Mountains.

    Much of the Sacramento uplift is composed of Paleozoic marine sedimentary rock, such as limestone and dolostone, and these carbonates accumulated on a stable marine shelf where shallow waters favored carbonate-secreting organisms, chemical precipitation, and the development of thick limestone sequences.

    From this overlook, we were able to see our next stop, White Sands National Park!