First-day road log: From Cortez, Colorado to Montezuma Creek, Bluff, Aneth and Four Corners
— Orin J. Anderson, Spencer G. Lucas, William L. Chenoweth, and Steven C. Semken

Altough outside of New Mexico, our assembly point is on the familiar turf of the Dakota Formation (Upper Cretaceous). As we begin the day's journey and head westward through McElmo Canyon, we will be descending stratigraphically from the position of the Dakota Formation. Excellent exposures of the Jurassic Morrison Formation and San Rafael Group are present along the route, with the oldest rocks, those of the upper Glen Canyon Group, being exposed at McElmo Dome, approximately 14 mi west of Cortez. From that point west, much of the terrain is developed on Morrison Formation, the Lower Cretaceous Cedar Mountain Formation and the Upper Cretaceous Dakota Formation.

At the Utah state line, we enter the petroleum-producing (Pennsylvanian production) areas of the Ismay and the Aneth fields. The route continues southwest to the San Juan River and thence westward to Bluff, Utah, our most distant point. At Bluff, we will have the opportunity to see the type area of some lithostratigraphic umts that Gregory (1938) named and originally included in the Morrison Formation.

The return leg of the journey will take us through the Four Comers Monument, where one can be in four states at once and yet remain on Morrison strata. Other features, such as the intrusive mass of the Carrizo Mountains and the Carrizo Mountains uranium-vanadium mining district to the south will be addressed at the Monument. From the Four Comers into Cortez much of the landscape is developed on the Upper Cretaceous Mancos Shale, a prelude to Day 2.