exdlich.] SWEETWATER DISTRICT DRAINAGE. 49 



rubber-boat he carried with him, which, after successfully passing the 

 greater portions of the rapids, was eventually capsized. 



Nortlwrn tributaries of the Sweetwater. — While within the mountains, 

 the Sweetwater receives a number of small streams, which rapidly swell 

 its volume. I^orth of South Pass City heads what has been called Wil- 

 loic Creel:. After a short run this discharges its waters into the Sweet- 

 water. A short distance farther east, near Atlantic City, Rock Creek 

 heads, which joins the river nearly south of Stambaugh. Eastward, 

 beyond that point a number of small streams run towards the Sweet- 

 water, but only few of them carry any water for the entire distance. 

 During the wet season many of them flow freely, but they begin to dry 

 up in June. From the plateau we found no water entering the river. 

 A number of small creeks exist within the plateau, issuing mainly from 

 springs, but they do not carry water for more than a few hundred yards. 

 An exception to this ride was found immediately south of the western 

 end of the Granite Hills. There we observed a stream of some size, 

 having a length of about 16 miles. At a number of points water was 

 found in the run, sometimes flowing, at other places stagnant. From 

 what we saw there, we inferred that this creek carried water during a 

 considerable portion of the year. At the mouth of the small canon 15 

 miles above the Three Crossings, this creek flows into the Sweetwater. 

 Provisionally, I shall designate it as Heron Creek. No tributaries of any 

 importance besides these were found on the north side of the river. 

 The drainage-area of the plateau is not very large, and the character 

 of the strata composing it is such that water easily soaks down into 

 them. 



Southern tribiitaries of the Sweetwater. — Few streams, comparatively, 

 of any size flow into the Sweetwater from the south. Within the hills 

 bearing the same name is the creek on which we camped in the narrow 

 Carboniferous canon. Eising in the isolated granitic hills south of the 

 river, this creek first follows an easterly course. On its way it receives 

 several small branches. A sudden turn changes its direction to the 

 north, and it enters the Sweetwater about 8 miles below Saint Mary's 

 Station. At the time we were there, June 30, it carried water through- 

 out its entire length. Isear its junction with the river the ground is 

 swampy, and we found no well-defined mouth of the creek. This stream 

 we have named Saint Mary's Creek. Along the northern slope of the 

 Sweetwater Hills there are a large number of small creeks, which start 

 in the gulches cut into the slope. As a rule, they only run for a short 

 distance, however, soon sinking in the loose sod nearer the river. Wher- 

 ever the timber extends far down the slope, there the water will remain 

 above ground for some distance. During certain seasons of the year 

 several of these streams discharge their water into the river, but at the 

 time of our visit (August) we found no water farther than a mile from the 

 base of the hills. Still farther east, in Elkhorn Gap, there is a good- 

 sized stream, which carries water to the river. Heading on the south 

 side of the hills, it curves along their base, passes the middle butte to 

 the eastward, and flows through the low gap. Bordered by grassy mead- 

 ows and receiving additions of water from a few small creeks, this stream 

 runs through a broad valley northward into the Sweetwater. It carries 

 water during the entire year, and, judging from the appearance of the 

 banks, must form a perfect torrent at certain seasons. It has been named 

 West Sand Creek. As farther west, so the hill-slope east of Elkhorn 

 Gaj> contains a number of short creeks. They carry a plentiful supply 

 of Avater until they emerge from the hills and lose it in the sandy soil 

 northward. At about one-third of the distance from Elkhorn to Whis- 

 4 a s 



