266 REPORT UNITED STATES GEOLOGICAL SURVEY. 
The Bull Lake Fork moraines are precisely like those above described, 
being heaped up on the planed-off surfaces of the Mesozoic and Tertiary 
deposits and reaching well up on the foot of the mountain to an eleva- 
tion of 1,200 feet or more above the stream. They reach out into the 
basin as far as Wind River, or a distance of nearly 10 miles, the deposits 
apparently inereasing in magnitude in that direction, where they soon 
conceal from view the subjacent geological deposits. The lake was 
formed by a low barrier which marks the site of a terminal moraine, 
similar occurrences being met with lower down the stream giving rise 
to a chain of water-expansions or lakelets. One of these low terminal 
moraines crosses the valley haif a mile or so above the lake, which the 
stream has broken through, forming a narrow passage where it shows 
a height above the water of about 30 feet and a breadth of 75 yards. 
Looking up into the mountain basin the Archean ledges present ex- 
tensive “glaciated surfaces and huge ridges of morainic origin. 
Allusion has already been made to the glacial phenomena prevalent 
on Little Wind River. The two inain branches of this stream cross the 
outer mountain ridge by independent canons, uniting in the plains be- 
low. Their exits from the mountains are accompanied by morainal 
ridges constituting prominent features in the magnificent view of the 
mountains as seen from the valley in the vicinity of Camp Brown. The 
barred sedimentaries appear on the mountain side in the interval be- 
tween the two streams. In the bed of the valley of the North Fork, just: 
below where it leaves the mountains, low parallel ridges of morainic 
origin are met with which may be remnants of medial moraines merged 
with terminal deposits. In the high blufis on the north side the lateral 
moraine rests upon a heavy bed of Pliocene (2) conglomerate which inter- 
poses a hundred feet between the glacial deposits and the tilted Mesozoic 
strata. The north-side lateral moraine attains an elevation of about 
1,500 feet above the stream, rising up on a high shoulder which breaks 
down in a precipice several hundred feet in height on the canon side. 
Within the broad and rugged mountain basin moraines of even greater 
magnitude were built up along the principal tributaries. The latter in 
places traverse beautiful tracts of grassy, forest-environed intervales, the 
region indeed abounding in scenic contrasts the most beautiful and 
sublime. 
Tufaceous deposits, &c.—Along the northeastern foot of the Wind River 
Mountains some interesting occurrences attributable chiefly to deposi- 
tions from springs issuing in the immediate border of the basin were 
met with, of which a brief account is embodied in the following pages. 
The first of these deposits occurs in the immediate neighborhood of 
Warm Spring Creek, where their origin is perhaps most clearly revealed. 
They extend to the southeast as far, at least, as Campbells Fork, and 
certain conglomeritic deposits with which they are here associated have 
similar, if not identical, recurrences still farther south to the neighbor- 
hood of Little Wind River. 
In the south side of Wind River, at Warm Spring Creek confluence 
and a few miles below, recent deposits of calcareous matter have been 
made by springs which have not yet altogether ceased flowing. Their 
deposit forms a light, porous rock retaining impressions of leaves and 
land snails of living forms, and cf comparatively limited extent in the 
low terrace bordering the intervale, 15 to 35 feet above the stream. As- 
cending Warm Spring Creek it is presently shut in by the bluffs of 
higher terraces that rise in two distinct levels. In the edge of the 
higher bench, perhaps half a mile above the mouth, the creek has eut 
through a mass of tufaceous limestone, where, on the east side, at an 
