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THE NORTHERN PACIFIC ROUTE. 
59 
West of the summit the surface descends to Richardton, the largest 
town between Mandan and Dickinson. 
a result of the success of dry f 
tively situated on the rolling upland plateau of 
western North Dakota and has abundant supplies 
of clay and lignite ready to be utilized in the building 
Richardton. 
Elevation 2,487 feet. 
tion 647. 
of a large town. 
This town has grown up as 
arming. It is attrac- 
From Richardton the railway winds through a gently rolling 
country and gradually descends to Heart River, which is reached 
at the village of Gladstone. 
the same valley that it left a few miles west of Man- 
dan, but the climb out of the valley and the descent 
Gladstone. 
Elevation 2,373 feet. 
St. Paul 550 miles, 
Here the railway is in 
back in again saved the railway several miles of 
track, although it involves some rather heavy grades. 
he valley of Heart River is comparatively narrow and is bounded 
by steep bluffs in which the rocks of the Fort Union formation are 
well exposed. At the little village of Lehigh (see 
Lehigh. 
Elevation 2,372 feet. 
iles. 
sheet 9, p. 64) a lignite mine has been in operation 
for a picket ie of years. The bed of lignite, which is 
from 6 to 7 feet thick, lies horizontal and is reached 
included trees of many kinds, shrubs, 
vines a 1 p ey 1 1 2 1 , | 
wth. Among the trees one of the most 
abundant types as regards kinds as well 
as individuals was the poplar (Populus). 
These were of an ancient type, with small 
rounded or heart-shaped leaves, and were 
most closely related to the living quaking 
aspen. Of the willow several species are 
known. — of several kinds were pres- 
ent, as wi s two species of hazelnut, 
both of which: are still living in the eastern 
u 
present, together with sycamores so like 
the living species as to be separated with 
difficulty. Figs were present, though not 
dogwoods, hickories, box acini mes 
viburnums, wax berri tch- 
hazels, Lape hee bitterweets, and 
many tha names. 
From this ota flora it is evident 
that what is now an less plain 
was then covered with splendid forests of 
hardwoods, interspersed with scattered 
conifers and ginkgos. From the presence 
of numerous and in many places thick 
beds of lignite it is clear that there were 
great swamps, and that these must have 
continued with but little change for long 
periods of time. It has bee ted 
that the product of heavily timbered 
woodland, when compressed to the spe- 
cific gravity of coal, would only amount to 
about one-fourth of an inch in thickness 
f this statement is 
even approximately correct, it is easy to 
calculate that a 4-foot bed of coal must 
have required about 20,000 years for its 
accumulation. 
Except for the presence of palms and an 
occasional fig, it might be presumed that 
the climate was not greatly different from 
that now prevailing on the Atlantic slope 
of North America—that is, cool temper- 
ate. which are found in the 
lower part of the formation imply, so far 
as the present distribution of palms indi- 
cates, a somewhat warmer climate, just 
as the numerous thick beds of lignite 
throughout the formation imply long- 
marsh conditions. 
- continued 
