14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
The tan volcanic siltstone unit of the Hendry Ranch member was 
found only along Badwater Creek north of Cedar Ridge and in a 
small area just north of locality 11 (sec. 10, T. 39 N., R. 92 W.). 
The siltstone is soft and forms poorly exposed slopes in contrast to 
the lower member, which forms badlands areas. The siltstone ranges 
in color from grayish tan to pale greenish gray, and gray; it is some- 
what limy throughout, poorly bedded, and irregularly jointed. At 
most places, two beds of white limy vitric tuff as much as 3 feet thick 
are present in the lower part of the sequence. The vitric tuff beds 
are highly lenticular and are missing at locality 16 (figs. 2 and 5). 
The siltstone unit contains much admixed volcanic material, however, 
particularly in its lower part. Lenses of bright-green volcanic-rich 
sandstone are present at some places. At locality 7 (figs. 2 and 5), 
medium-grained to coarse-grained volcanic sandstone at the base of 
the siltstone unit lies on greenish-gray claystone and siltstone. 
Lenses of conglomerate and coarse-grained sandstone made up of 
pieces of Pre-Cambrian and Cambrian rocks as much as I foot in 
diameter are common in the lower part of the siltstone unit and in 
the upper part of the greenish-gray unit. In some places, fragments 
of light-grayish-green siltstone from the lower unit are included in 
lenses of intraformational conglomerate in the lower part of the 
siltstone unit. 
The change from greenish-gray rocks below to tan siltstone above 
takes place within a few feet, but no consistent criteria were found 
for separating the two units along their contact. The most usable 
contact for field mapping is where the material in which the con- 
glomerate lenses are included changes from the gray claystone and 
siltstone of the lower unit to the tan siltstone of the upper unit. 
Where conglomerate or coarse-grained material is not present, this 
change occurs about at the base of a bed of white vitric tuff. How- 
ever, in local areas, there is prominent channeling at the contact. This 
channeling may account in part for the thinning of the underlying 
lower greenish-gray unit from place to place. 
The white clastic facies—The white clastic facies (fig. 3) con- 
sists chiefly of material eroded from the Owl Creek and Big Horn 
Mountains and deposited directly adjacent to the mountains or in 
reentrants within them. Volcanic material is mixed in different 
amounts with the derived clastics but the essential characteristic of 
the rocks of the white clastic facies is the general absence of volcanic 
material compared to the rest of the Tepee Trail formation, The 
white clastic facies is particularly well developed along the south side 
of the Owl Creek Mountains and is conspicuous in the area embraced 
