434 A Contribution to the Zoology of Montana. [July, 
and often precipitous banks, and the elevated plain on the north | 
side gives uninterrupted views of great beauty. To the north-east 
the red granite masses of the Bear’s Paw mountains obstruct the 
view, and to the south, mountains of various outlines form the 
horizon. These are the Belt, Judith and Snowy ranges, and they 
enclose, with the bend of the Missouri river, an extensive plain. 
From this plain rise several table-topped masses, evidently rem- 
nants of old strata protected by an outflow of lava. 
At the mouth of the Judith river the special object of my 
exploration began to claim attention, viz: the investigation of the 
beds of the Judith River Lignite formation and the extraction of 
their fossils. The results of this work are given in the Bulletin 
of the U. S. Geological Survey of the Territories, F. V.. Hayden 
in charge, Vol. 11, No. 3, 1877. The exploration included the 
valleys of the Judith river, Dog creek and Two Calf creek, and 
the canyons of the south side of the Missouri as far east as 
Amell’s creek, and the corresponding situations on the north side 
of the river on the return to Fort Benton. These streams carve 
deep canyons through the yielding lacustrine and marine strata 
which underlie the plains, which often present scenery of terrible 
desolation and grandeur. The bluffs of the Missouri reach the 
height of one thousand feet in many places, and in but few locali- 
ties are passable by wagons. The labyrinths of their branch 
canyons are only passable by pack animals, and the high land 
can only be successfully reached by a most careful discrimination 
of the main “divides,” or water-sheds, from the innumerable 
spurs which diverge from them. 
The plains of this region are neutral ground between the Crow 
and Sioux Indians, who are ever at war; and they have not been — 
regarded as a safe abode for white settlers. The only Americans 
in the region are the few wood-choppers on the Missouri bot- 
toms, and the freight and other agents of the Missouri river 
steamers and shipping houses, who for a few months of every 
year are stationed at Cow island. The country is practically left, : 
to the game, which is here generally unmolested excepting by 
occasional hunting bands of Indians. ; 
While geological and palæontological exploration was the 
primary object of the expedition, a few zodlogical notes were 
* taken, which I here record. 
_ Mammals—One of the characteristic iainih of Montana 
