48 EEPOET UNITED STATES GEOLOGICAL SURVEY. 



DRAINAGE. 



Sweetwater drainage. 



The Sweetwater Eiver lieads about 10 miles northwest of Stainbaugh 

 Peak in the Wind Eiver region. Flowing through canons of short 

 length and through narrow valleys it emerges from the western slope of 

 the mountains into the rolling metamorphic area. Eeceiving water from 

 a large number of swift mountain streams, the river has attained a con- 

 siderable size upon reaching the open country. At first it passes through 

 a number of small canons, deeply cut into the schists of that region. 

 While within the mountains the river has a course nearly south. This 

 is changed to an easterly one after it has emerged into the open country. 

 Flowing eastward, south of South Pass City, it is crossed by the stage- 

 road. From there on the Sweetwater retains a general course of nearly 

 west to east, varjdng probably 10 miles on either side in its turns. Ap- 

 proximately the river follows north latitude 42° 30'. After flowing 

 past Camp Stambaugh, about 10 miles south of it, the stream en- 

 ters what we have called the Little Sweetwater Canon. It is there 

 inclosed by steep walls of metamorphic rocks. At this point we 

 have reached the southeastern termination of the foot-hills of the 

 range. A vertical rent in the rocks has opened a passage for the stream, 

 which rushes through it with great violence. Descending the rather 

 steep slopes of the Mils at this locahty, a part of which belong to the 

 older sedimentary groups, we reach the valley proper of the Sweetwater. 

 A few miles below the canon we find Saint Mary's ranch. This, at the 

 present time, presents but the ruins of an old stage station. From there 

 the river winds eastward lazily through its vaUey. Bordered on either 

 side by bluffs, the low-land is covered with grass and willow brush. About 

 15 miles above the Three Crossings we meet with another small canon. 

 A gap in quartzitic sandstones, sufficiently narrow to force the river 

 through it with a rush, is formed by vertical walls about 120 feet in height. 

 After tumbling over the bowlders the Sweetwater enters a comparatively 

 wide valley, containing an abundance of good grass. By this time we 

 have arrived within the Granite Hills. Bordering the river on the north, 

 they determine, in a great measure, its course. Following down the val- 

 ley, we eventually reach the Three Crossings, located about at west lon- 

 gitude 107° 45'. Here the wagon-road crosses the stream three times in 

 rapid succession, whence the name. A grassy bottom, about 2 miles in 

 length, is found on the south side of the river, which closely hugs the 

 granitic hills to the north. From that point downward we notice several 

 sharp turns, induced by the projecting or receding masses of gTanite. In 

 a few instances we find that small gaps have been formed in some of the 

 transverse ridges. Taking advantage of these, the Sweetwater shortens 

 its course by passing through them. Flowing past Cloven Peak, it runs 

 closely along the southern border of the granites, until, finally, it crosses 

 this irregular range by way of the Devil's Gate. This latter is a vertical 

 opening in the rocks, fiUed almost entirely by the stream. Perpendicu- 

 lar walls enclose the river, rising to a relative elevation of about 400 feet. 

 Immediately after i)assing through the gate the Sweetwater turns to the 

 northeast for a short distance, thus effecting a crossing through the 

 Granite Hills. By following this turn for about 5 miles we reach Eock 

 Independence, located near west longitude 107°. From there the river 

 flows about 10 to 12 miles farther to its junction with the North Fork of 

 Platte Eiver. It passes through a narrow caiion in a series of rapids. 

 Here it was that Fremont made his memorable trip downstream, in the 



