52 LARAMIE BASIN, WYOMING. 
Its course is from northeast to southwest. At a point along the 
main road 3 miles northeast of Rock River station a local increase in 
uplift causes the appearance of a small outcrop of Niobrara. On the 
west side of the Rock Creek anticline there is a narrow syncline in 
which the lower shales of the Montana extend for some distance into 
T. 22 N., R. 75 W., and the ridge of Casper formation is deflected 
eastward in T. 23 N., R. 74 W. The dips on the southeast side of 
the uplift are 10°; on the northwest side they range from 70° to ver- 
tical. The axis of this anticline passes a short distance south of 
Boswell Spring, where the dip is 20° N., 72° W., and it is a moderately 
prominent feature in the ridges of Casper limestone on the mountain 
slopes east of the spring. 
COMO ANTICLINE. 
The Como anticline extends from the Laramie Mountains far across 
the Laramie basin on a nearly west-southwest course. It causes an 
extensive deflection in schists and limestones in the front ridge south- 
west of Garrett, and deflects the Chugwater red-bed outcrop far to the 
west beyond the margin of Carbon County. The prominent Como 
Ridge, on the southern slope of the uplift, is due to the Cloverly rising 
on a gentle dip — 8° to 10°. It presents a precipitous face to the 
north, at the top of long slopes of the Morrison, Sundance, and Chug- 
water formations. This low dip is general on the south side of the 
uplift, but on the north side the dips approach the vertical. The 
flexure pitches down steeply at the southwest end of Como Ridge, 
where the structural relations are clearly shown by the curving out- 
crops of the upper sandstone of the Benton (Carlile) along the Union 
Pacific Railroad. Four miles southeast of Medicine Bow the flexure 
rises again abruptly for a short distance in a low ridge, in which beds 
from Niobrara to Morrison are exposed. On the north side of the 
Como anticline there is a syncline which carries the lower shale of the 
Montana in the region northeast of Medicine Bow and a wide area of 
Benton shales farther northeast. It finally passes into an angle in 
the mountain front west of Garrett, where beds from Benton to Cas- 
per are covered by Tertiary deposits. 
FLATTOP ANTICLINE. 
North of Medicine Bow there is a prominent uplift, on the crest of 
which there is a summit known as Flattop. From Medicine Bow 
northward to this point the beds rise in regular succession — first the 
Niobrara, which appears in the river bank at the north end of the 
iron bridge ; then the prominent upper sandstone of the Benton, which 
causes a sharp outlying ridge (see PI. VI, B) ; then slopes of Mowry 
shale on a second ridge in which appear formations from the Benton 
