FISH-CULTURAL INVESTIGATIONS IN MONTANA AND WYOMING. 
15 
mountains some 15 miles east of Deer Lodge. Flowing through rocky gorges in the 
upper ] >art of its course, and through rather rough meadow land in the lower portion, it 
unites with the Deer Lodge River at the city of that name. The bed of the stream is 
throughout very rough and rocky, but the banks are lined with a heavy growth of 
cottonwoods, alders, and other small trees and bushes. It seems to be well supplied 
with insect larv® and other suitable food for flsli, and is a most excellent trout stream. 
The seining that we did here was very unsatisfactory, owing to the roughness of the 
bottom and the extreme swiftness of the current; however, we took over 30 trout and 
a great many blobs. Quite a number of trout were also taken with the fly. None of 
the trout taken weighed over half a pound. 
In some very small ponds along the creek we found a great many frogs, and insect 
larva? literally swarmed in these pools. A few snakes (Eutcenia sp. ?) were seen here. 
Quite a good deal of the water from Cottonwood Creek is used for irrigation, and the 
city of Deer Lodge receives its water supply from this stream. Up to the present 
time a little mining has been carried on along the upper course, but it has practically 
ceased now, and there is no great probability that the water of this creek will ever be 
in danger of contamination from that source. 
Deer Lodge River . — This river has its origin in numerous small streams in the hills, 
chiefly to the westward of Butte City and on the divide, upon which also rise many of 
the affluents of Jefferson Fork of the Missouri. Flowing northward through a very 
beautiful and rich agricultural valley, it joins the Little Blackfoot River at Garrison, 
about 45 miles north of Silver Bow. We examined the Deer Lodge River throughout 
the greater part of its course. At Deer Lodge we found it to be 57 feet wide, 3 feet 
deep, and to have a current of 4 feet per second; this gives a flow of 307,800 gallons 
per minute. The temperature of the water at 10 a. m., July 23, was 59°; that of the 
air, 78°. 
Throughout most of its course it has a very swift current. The bed of the stream 
is chiefly of coarse gravel and larger rocks. In some portions where the current is less 
swift the bed is made up of a constantly shifting mass of fine silt-like material, prob- 
ably from the concentrators and reduction works at Anaconda and Butte. Throughout 
the entire length of this river the water is full of this solid matter in suspension. The 
amount of solid matter carried down by the Deer Lodge River from this source must 
be very considerable, and of course proves fatal to all kinds of fish life. We seined 
the river very thoroughly in the vicinity of Deer Lodge and did not find any fish 
whatever. 
This stream is said to have been well supplied with trout and other fish, but none 
have been seen since the concentrators began operations. Other life was also scarce ; no 
living mollusks or crustaceans and but few insect larvae were seen. Upon a sandbar, 
below the town of Deer Lodge, we found a few dead shells of Margaritana margaritifera 
Linn., but careful search failed to discover any living specimens. The banks, usually 
low, are covered with a pretty heavy growth of alders, willows, and other small bushes. 
Except this fringe of trees along the streams, most of the Deer Lodge Yalley is more 
or less rolling prairie or meadow hind. In suitable places along the stream frogs were 
quite plentiful. 
In its course from Silver Bow to Garrison the Deer Lodge River receives a great 
number of small streams from the mountains on each side of the valley. From the 
east come Browns Gulch, Silver Bow, Peterson, Cottonwood, and Freeze-out, creeks; 
