30 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
deeply scored by the erosion of the brief rainy season. Except in the Colorado and 
in a few brooks andiionds ]iear the crest of the Wahsatch, there are no fishes in east- 
ern Utah. West of the divide of the Wahsatch lies the Great Basin. This is a high, 
arid plain, largely alkaline, and crossed by nnmerons short but abrupt mountain chains. 
E.— SALT LAKE BASIN. 
The lowest part of this basin is occupied by the Great Salt Lake, while other 
depressions are occupied by other lakes or alkaline sinks, also without outlet. The 
largest of these in Utah is Sevier Lake. Into these lakes and sinks flow the waters of 
multitudes of clear streams and springs having their source in the mountains. Most 
of these streams are well stocked with trout and whiteflsh in their npper courses. The 
water farther down is now nearly all consumed by the irrigating ditches of the Mormon 
settlers, and in Utah, as in Colorado, millions of young trout are each year destroyed 
by venturing out into these ditches, whence they are scattered over the fields and left 
to perish. All the valleys of western Utah were formerly covered by the waters of a 
great post-glacial lake known to geologists as Lake Bonneville. The evidences of the 
former existence of this lake are everywhere visible in the form of terraces on the sides 
of the mountains at a considerable height above the present levels of Utah Lake and 
the Great Salt Lake. Lake Bonneville had probably its outlet to the north through 
the Snake Kiver. The former connection of the now isolated lakes in the Great Basin 
must explain the close similarity in the fish faunm, but we can not tell how close this 
resemblance is until the fishes of the Great Basin of Nevada, the bed of the former Lake 
Lahontan, are thoroughly investigated. Collections weremadeby ns at different points 
in the Salt Lake Basin and in the basin of the Sevier Eiver at Juab. 
1. Utah Lake . — Utah Lake is about 25 miles long by 10 broad, of irregular form, 
and surrounded by high mountains. It is shallow near the shore but deep in the 
middle and in its channels. The surface water is in summer quite warm, while on the 
bottoms it is very cold. The lake is extremely low in summer, there being but little 
water running in the outlet. The water is then of a milky blue color and decidedly 
alkaline. Our collections were made with a long seine, kindly furnished to us by Peter 
Madsen and his sous, of Provo. This seine was used in a deep channel in the south- 
western part of the lake below the mouth of the Spanish Fork. Fishes taken in the 
lake are marked U in the following list. 
2. Provo River . — The Provo Eiver is a considerable stream, the largest rising in 
the Wahsatch range. In the upper course it contains no fishes except trout. Where 
it leaves the canon at the foot of the Wahsatch it is very clear aud icy cold (tempera- 
ture about 53°). It flows over a bottom of rounded shingle aud small boulders. In 
and immediately below the cafiou it contains only trout and some whiteflsh. The 
bottom has no vegetation. Lower down towards the town of Provo the water becomes 
gradually warmer; the bottom is covered with plants aud the banks lined with bushes. 
The bottom is here of flue gravel and the temperature about 63°. The species taken 
at this point above the city are marked P in the list. Still lower down the water is 
all drawn off for irrigation, and only the seeiiage fills the river bed. Near the mouth 
of the river, near Madseids farm, the bottom is of fine gravel, sand, and mud ; the water 
is sluggish and warm (temperature about 78°). The fishes found here are marked M. 
In Mr. Madsen’s carp pond, a muddy i)ond formed from artesian water, we found 
Leuciscus atrarius and Heniitremia phlegethontis very abundant. They had come in 
