NO. 4 GEOLOGY, WIND RIVER BASIN—TOURTELOT 15 
by the forks of Dry Creek (Tps. 39 and 4o N., Rs. 92 and 93 W.). 
The facies is prominent also between the westernmost fork of Dry 
Creek and Hoodoo Creek. In the Dry Creek drainage, the facies 
consists of very light-gray to white pebbly and sandy claystone and 
very clayey sandstone. The rather uniform admixture of sand and 
pebbles gives the claystone a somewhat cementlike appearance. Al- 
though some of the sandstone beds show sorting and bedding, in 
general, the facies shows an absence of sorting during its deposi- 
tion. Pebbles of quartz and feldspar and abundant sand grains are 
scattered through the claystone like raisins in a pudding. The very 
poor sorting and general lack of bedding is suggestive of mudflows 
but no other evidence of this kind of deposition was recognized. Most 
of the clay beds in this sequence weather to a soft puffy surface and 
the clay in such beds probably is bentonitic. Some of the light-colored 
claystone is hard and only slightly plastic when wet. The forks of 
Dry Creek drain an area in the Owl Creek Mountains made up chiefly 
of pink to brown granite and the feldspars in these rocks could have 
yielded kaolinitic weathering products during Tepee Trail time. Such 
claystone may be kaolinitic but no mineralogical study was made. 
East of Hoodoo Creek, the facies is yellow to brown and contains 
several distinctive dull-red beds. Cobbles of granite and dark-colored 
gneiss, phyllite, and schist are abundant. The generally more som- 
ber color of these exposures and lack of the white claystone charac- 
teristic of the Dry Creek area is believed to be related to the dark- 
colored gneiss, schist, and phyllite in the area drained by Hoodoo 
Creek. The lateral gradation of the clastic material eroded from the 
mountains into the green and brown volcanic sediments of the Tepee 
Trail is well displayed along the sides of pediment benches in the 
area between Hoodoo Creek and the west fork of Dry Creek. 
The white clastic facies is typically developed along Lysite Creek 
(T. 40 N., R. go W.) and was derived chiefly from Paleozoic rocks. 
Red colors are common in the facies near where it overlaps Pennsyl- 
vanian and Permian rocks in the mountains. This is particularly no- 
ticeable in the reentrant in the Big Horn Mountain front in T. 39 N., 
R. 88 W., north of locality 1 (fig. 2). 
The equivalence of outcrops of the white clastic facies and the 
Hendry Ranch member of the Tepee Trail formation can only be 
inferred. The Hendry Ranch member is found only in areas isolated 
from the Tepee Trail strata adjacent to the mountains. At the same 
time, the equivalence of material of the white clastic facies and the 
Hendry Ranch member is believed certain because material of the 
white clastic facies is found in the mountains at altitudes much above 
