690 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



Uintas forms the boundary, through which the Green Eiver winds in deep 

 gorges. The southern half of the western limit is as ill-defined as on the 

 east, the land rising gradually to a plateau which separates the Green 

 from the drainage of the Bear. Proceeding north, this plateau rises, 

 becomes cut into long, narrow, meridional ridges, which I have named the 

 "Absaroka Eidges," and which, farther north, are eroded into mountains, 

 forming what is known as the Wyoming Range. At the east base of / 

 this range, the lip or rim of the basin is very strongly marked, sloping ( 

 gradually down to the valley on the east and breaking off abruptly on \ 

 the west, leaving a narrow meridional valley, crossed by numerous 

 branches of the Green between the rim and the mountains. Within my 

 district, the Green occupies a position several miles west of the middle 

 line of the Basin. 



In the upper part of the Basin, the Green receives numerous large 

 branches. Most of the streams from the western slope of the Wind 

 Eiver Mountains collect into one large river, the New Fork, fordable . 

 with difficulty even at low stages of the water. This joins the main 

 stream in latitude 42° 34' 00", longitude 109o 58' 30". The country in 

 this upper part of the Basin is devoid of timber, but well grassed and 

 watered. The soil, however, is gravelly, and the elevation is too great 

 to allow it to be used for agriculture, or for a cattle range, except in 

 summer. 



From the Wyoming Eange and the Absaroka Eidges, which may be 

 considered as its southern extension, the Green receives imuierous large 

 branches, which, after tortuous courses through the mountain caiions, cut 

 their way through the rim of the Basin and thence meander peacefully 

 eastward to join the main stream. The principal of these western 

 branches of the Green, commencing at the north, are Lead, Horse, 

 Marsh, White Clay, Bitterroot, Piney, La Barge, Fontenelle, and Slate 

 Creeks, and Ham's Fork. All these streams, with the sole exception of 

 Slate Creek, carry considerable water throughout the year. Lead and 

 White Clay Creeks are the only ones of these which do not reach the 

 moimtains, and they are the only ones of these western branches of the 

 Green which, heading in the Basin rim, are constant runners. In July 

 the former is about 6 feet in width, 6 inches in depth, and carries not 

 more than 10 cubic feet of water per second. This creek enters the 

 Green on the north line of my district. Above and below its mouth the 

 Green is a rapid, clear stream, with a current of about 5 feet per sec- 

 ond. On either side, the country stretches back in great level expanses 

 but slightly raised above the river, occasionally varied by hill-masses. 

 The soil is gravelly, with low sage and some grass. The river flows 

 south for 6 miles, then turns east and hugs closely the base of a group 

 of hills, the remains of a high bench, on the left. Near the foot of this 

 eastern bend. Horse Creek joins it. 



The country between Lead and Horse Creeks is mainly flat, but 

 diversified to some extent by the remains of benches of a higher level. 



Horse Creek is one of the largest of these western branches, car- 

 rying, in July, nearly 200 cubic feet of water x)er second, and fordable 

 in high water with the greatest difficulty, It drains quite a large 

 area of the Wyoming Eange, collecting all its small aiSuents into 

 two main branches in the valley behind the Basin rim ; these two forks 

 break through the rim, uniting in the basin several miles above the mouth 

 of the creek. For four or five miles this stream and the Green flow 

 side by side in the same broad bottom-land before uniting, forming 

 one of the finest areas of meadow-land on the river. Here both streams 

 are very sluggish and winding, with many sloughs, backwaters, chau- 



