THE NORTHERN PACIFIC ROUTE. 75 
several years ago, and bones of these animals may be seen occasionally 
in riding about the country. 
Forsyth, the county seat of Rosebud County, a district terminal of 
the Northern Pacific Railway, is one of the thriving towns in the 
Yellowstone Valley. It was named for Gen. J. W. 
Forsyth. Forsyth, one of the military pioneers of this coun- 
iter ga try. Opposite the town the Chicago, Milwaukee & 
St. Paul 701 mites. St. Paul Railway, which has followed Yellowstone 
River from Terry, leaves the valley and goes in a 
northwesterly direction to the Musselshell Valley in the vicinity of the 
new towns of Musselshell and Roundup. 
Beyond Forsyth an anticline crosses the Yellowstone Valley, but 
it is not so distinct as the one above Glendive. The first indication 
that the traveler may observe of a change from the Lance formation, 
which is at railway level from Terry to Forsyth, is that after passing 
Armells Creek, just beyond milepost 130, the width of the valley 
suddenly increases and the bluffs lose their rugged character. These 
features indicate the presence of softer rocks, and while the formation 
containing them is not visible from the train a close examination of 
the bluffs would show that they are composed of dark shale—the 
same dark shale that the traveler saw at Cedar Creek, above Glendive. 
This shale normally underlies the Lance, and its presence near railway 
level here means that the rocks rise west of Forsyth and the next lower 
formation is brought to view. 
* The dark shale noted near Glendive supposed to represent the cut edges of the 
is called the Pierre shale, but the dark | formations as they lie in the ground. 
shale that makes its appearance near In the Black Hills, and so far as known 
Howard and is said to be the same as the | at Glendive, the Upper Cretaceous rocks 
Pierre, is called Bearpaw. ‘The change | begin with the Dakota sandstone at the 
to Billings, Mont. 
in the Cretaceous formations along an | base, resting upon the Lower Cretaceous. 
east-west line from the Black Hills to | Over this are two great shales (Benton 
Billings,- Mont., and the reason for the | and Pierre) and a limestone (Niobrara) 
introduction of new names for the fcrma- of marine origin, and capping all is the 
tions are explained by figure 9, which is | Lance, a fresh-water deposit. 
om 
