84 GUIDEBOOK OF THE WESTERN UNITED STATES. 
characteristics by which it may be recognized and identified, but it 
contains fewer beds of sandstone, and consequently makes smoother 
hill slopes than the underlying Claggett formation. The slopes com- 
posed of the Judith River formation have a whitish-gray tint and are 
rather monotonous in color and appearance. The rocks composing 
the upper part of this formation are well exposed in Countrymans 
Bluff, between mileposts 37 and 38. Here the rocks are undoubtedly 
of fresh-water origin, as they contain numerous fragments of fossil 
plants such as could have been deposited only either on land or Ina 
bodies of fresh water. 
The continued westward dip of the rocks brings the next higher 
formation (Bearpaw shale) to water level in the vicinity of Columbus. 
It can not be seen near the railway, but is well exposed 
Columbus. a mile north of the town. This shale crops out in the 
Elevation 3,624 feet. valley of Keyser Creek north of the railway and along — 
St. Panl933 mies, the foot of the ridge that begins just across the river 
from Columbus and extends southeastward as far as 
LAN FOR: 
Yy UY LLL set 
Api INLET TSOP OP 
—— Bearpaw Shae ——— 
SSS —————— ———— 
YM Yudith River formation TPe shafe= 
ade 
LLLLLL LL, Claggett farmation <= 
se Qle serOstonen pie ei eee 
FIGURE 12. 
—Cross section to illustrate the change in the formations between Terry and Livingston, 
Mont. 
stone of great excellence. This stone has been us 
tion of buildings in the n 
Helena. 
These sandstones cap Bensons Bluff, 24 miles west of Columbus, 
and come down to water level near milepost 43. The dips here are 6° 
to 8° to the west, but they flatten within a short distance and the 
rocks are practically horizontal. 
The traveler ma 
® 
=¥ 
— 
5 
ot 
Er 
® 
2 
rs) 
5 
n 
a 
cs 
