230 
GUIDEBOOK OF THE WESTERN UNITED STATES. 
dotted with farms, each protected by a line of tall poplars that may 
be seen far across the valley. Utah Lake, a body of fresh water 30 
miles long and 6 to 10 miles wide, lies in the middle of the basin, 
lower levels they left Ress the shapes 
thei a ha The base of 
h surviving beat cell is a hori- 
zontal line, and so is the crest of each 
beach, bar, and spit, and these features 
mountains that were once islands in 
the lake 
“In rising and falling the waters 
lingered at many levels, and so there 
are many ancient shore lines, but two 
h 
est of all is the Bonneville shore line, 
and 375 iil lower lies the Provo shore 
line. The Bonneville line represents a 
relatively on stand of the water and 
th pper bo 
All the slopes below it have been more 
or less modified by the waves, but 
the slopes above it retain the shapes 
which had been given them by other 
agencies. The Provo line represents a 
long stand of the water and is conspic- 
uous because it is strongly sculptured. 
“Tn all the early history of the great 
lake its basin was closed, like that of 
the modern lake. The water surface 
rose and fell in response to climatic 
team like that of its modern rem- 
oscillations by creating an outl 
owest point of the basin’s rim was at 
Red Pass [130 miles by rail 
north of Salt Lake City], and when 
the water rose above that level the 
came part of the dra sae system of 
the Pacific star 
“The formation at the summit [of 
ormed. 
of the channel increased ‘aa yolume of 
the stream by lowering the outlet = 
the lake; the greater gs m was m 
e cha peak sia 
ve two causes reson Ne un the 
a 
rie volume of water discharged before 
the flow became steady was enough to 
supply Niagara ees for 25 years, but 
e record of the torrent’s violence 
leads to the belief eat it lasted for a _ 
much shorter period. * * 
The draining of the lake down to 
the Provo level reduced its area by | 
op 
was 
outlet. 
4 
outlet channel ran dry, the lake basin 
was again separated from the drain- 
age system of the Pacific, and the lake 
began to shrink. So long as there was 
outflow the water was ie but when 
accum 
the water of the present lake a concen- 
trated brine. 
“At times in the history of the lake, 
especially while the Provo shore line 
gz t tributary 
was being -fo , the 
streams brought down 
gravel, they pped at their 
mouths, building deltas. When 
wate deposits remained 2S 
fan-sha nches having feep 
be 
The streams that built them 
dug channels through them. * ** 
