678 The Great Salt Lake in Former Times. (November, 
The ancient beaches, or “ benches” as the inhabitants call 
them, which indicate the former levels of the lake, at once attract 
the attention of the traveler soon after he leaves Ogden for Salt 
Lake City. “ While some of the benches are better marked 
than others, no number can be assigned to the successive shore- 
lines from the highest to the modern. Upon gentle slopes many 
more can be detected than on steep, and they are of all grades 
of distinctness. It is doubtless true that some, which are at cer- 
tain stations conspicuous, as compared to others, are elsewhere, 
from local causes, inconspicuous ; but there are two lines that can, 
at nearly every point, be recognized as far more strongly traced 
than any others. One of these is the highest of all, the Bonne- 
ville beach. The other occurs about three hundred feet lower, 
and this we have found it convenient to entitle the Provo beach, 
drawing the name from the town of Provo, on the shores of Utah 
Lake, near which it is especially well exhibited. These tell us 
that, during the progressive subsidence recorded by the entire 
series, there have been two marked epochs, perhaps many thou- 
sands of years in duration, through each of which a constant 
water level was maintained. The level of Great Salt Lake, like 
that of other lakes without overflow, is notoriously inconstant, 
for the obvious reason that it depends on the ratio between pre- 
cipitation and evaporation over a limited area, factors which di- 
verge, and change their conditions of equilibrium, with every 
fluctuation of annual mean temperature or humidity. It is diffi- 
cult to imagine that so unstable a climatal equilibrium was main- 
tained for the time that was consumed in the production of either 
the Bonneville or the Provo beach, and, before we accept such 
explanation of their origin, we are led to inquire whether at 
these levels the stage of water was not regulated by an overflow. 
The coincidence of one of the constant levels with the highest 
water stage of all renders the presumption of an outflow at that 
stage especially strong. With these considerations in view, We 
endeavored, in tracing the outline of the lake, to discover its 
point of discharge, but without success. Our examination was 
almost exclusively confined to the southern half of the lake, and 
points to the conclusion that no outlet existed toward the Colo- 
rado River. At one low point of the southern rim, near Hebron, 
Utah, the observation was not so complete as was t 
and the question may be considered as not definitely settled. 
Prof. O. C. Marsh informs me that he has discovered, OD the 
northern shore of the lake, an outlet leading to the Snake River, 
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