RECONNAISSANCE IN COLORADO AND UTAH 645 
careous.layers between. ‘The latter are often nodular in development 
and a pure blue limestone like that of the San Juan region was 
not seen. In color these beds are apt to be darker red than the mas- 
sive sandstones above and below, but some layers are gray or yellow- 
ish. These beds are seen in Fig. 3 at the base of the sandstone mass. 
Below the floor of Dry Valley is the lower La Plata sandstone in 
a thickness of about 250 feet. It is well shown in Cafion Colorado,* 
(Newberry) and its branches, through which the drainage of Dry 
Fic. 1.—‘‘Casa Colorado” (Newberry). In Dry Valley, Utah, near Cafion 
Pintado. Made of friable sandstones of the upper La Plata formation, Jurassic. 
Exhibits the alcoves which are very common in this sandstone in the Grand River 
district. Photograph by W. H. Jackson. 
Valley and the southwest slope of the La Sal Mountains enters Grand 
River. 
The lower La Plata sandstone of the Grand River region is more 
indurated than the upper and is specially distinguished by its cross- 
bedding. It is light pink or gray, of even fine grain, but is not so 
notably uniform as the upper. Fig. 5 illustrates a characteristic 
bank of this sandstone on a small tributary of Cafion Colorado. 
t The Hayden Atlas maps apply this term to the broad shallow part of Dry Valley 
but on the sketch map of Peale’s report for 1875 the name is applied in accordance 
with Newberry’s usage. 
