1879. | A Contribution to the Zoölogy of Montana. 433 
an expedition which I undertook in the summer and autumn of 
the year 1876. I left Franklin, Utah, by the Helena stage, which 
_ Carries its passengers through parts of Idaho and Montana, 
reaching Helena in four days from the time of starting. The 
route first traverses the rolling country of Bear river, and then 
enters the sandy lava desert of Eastern Idaho.’ Passing this 
inhospitable region, we cross the main range of the Rocky 
mountains and enter Montana by the Red Rock valley, which is 
watered by one of the creeks which form the heads of the Mis- 
souri. Here commence the beauties of Montana scenery. The 
numerous parallel ranges of low mountains are capped by masses 
of lava, the remnants of an ancient outflow that once covered the 
country. The faces of this rock are vertical, often approaching 
columnar, and generally possess a serrate crest. The slopes 
below them, and the lower valleys, are beautifully green. Before 
reaching Helena a portion of the granite region is passed over. 
Here the scenery is of a different character. The more yielding 
material of the rock has given the hills more rounded forms, and 
huge masses of weathered boulders, piled in the most grotesque 
manner, are often seen. The timber is more abundant, and the 
hills abound in game, especially grouse (Tetrao obscurus, etc.). 
On their sides several species of Sciuride are numerous. 
Continuing beyond Helena to the north-east, the Palzozoic 
region is reached. The stage route for Fort Benton passes through 
the Prickly Pear canyon, a narrow pass of a thousand feet in 
depth, between great walls of carboniferous rocks. After issuing 
from it and crossing a high mountain, the stage descends to the 
plains. Previous to visiting this region, I had not realized the 
fact that the same plains with which I had become familiar in 
Kansas and Colorado, extended west and north of the Missouri 
river, with all their peculiar scenery and products ; the buffalo 
grass, the prairie dog and antelope, the yelping coyote, the owls, 
the prairie rattlesnake and the herds of bison. At Fort Shaw 
the Rocky range towers grandly on the western horizon, and on 
the east the Belt mountains rise abruptly in magnificent propor- 
tions from the level plain. 
The road thence to Fort Benton is varied by ponds and “slews” 
whose proportions depend on the quantity of the rains. These 
are the homes of numerous Siredons, Speas and toads. eee 
From Fort Benton eastward the Missouri flows between high 
