First-day road log: From Cuba to La Ventana, San Luis, Cabezon, Mesa Portales, Mesa de Cuba and return to Cuba
— Spencer G. Lucas, Thomas E. Williamson, Larry N. Smith, Wright-Dunbar, Robyn, Hallett, Bruce, Barry S. Kues, Gretchen Hoffman, Adrian P. Hunt, David W. Love, Virginia T. McLemore, and R. F. Hadley

Today's route begins by driving south from Cuba toward the eastern edge of the San Juan Basin. In so doing, we descend from the Paleocene strata on which Cuba is built to Upper Cretaceous nonmarine and marine strata at the La Ventana rest stop on NM Highway 44 (Stop I). Here, we examine the Point Lookout delta and discuss coal and uranium resources in the La Ventana area.

From Stop I the route continues south and then southwest to Stop 2 near San Luis, where we investigate the parasequence stacking in Point Lookout shoreface sandstones. Stop 3, for lunch, is at Cerro Chafo, a partially dissected remnant of a tuff ring just southwest of Cabezon Peak. Here, we will examine the igneous geology of Cerro Chafo and discuss the Rio Puerco necks. We also will examine the El Vado Sandstone Member of the Mancos Shale . The next segment of today's route retraces to north of La Ventana and then proceeds west to Mesa Portales. Here, at Stop 4, the discussion focuses on younger Cretaceous rocks (Pictured Cliffs Sandstone and Fruitland/Kirtland Formations) as well as the Cretaceous-Tertiary boundary.

From Mesa Portales, the route proceeds west and then turns sharply northeast to Stop 5 at Mesa de Cuba. This stop is at the type section of the Paleocene Nacimiento Formation and focuses on silcretes, Paleocene stratigraphy and the Paleocene-Eocene boundary.