GANNETT.] THE BLACKFOOT BASIN. 695 



pn. In tliis valley it receives several large brandies from the Salt 

 Eiver Kange, and two, Crow and Smoking Creeks, from the hills which 

 limit its valley on the west. 



The valley has a length of forty-five miles, with an average width of 

 about five miles. Its surface is flat and unbroken, except in one place, 

 where there is a broad hill or bit of plateau which has forced the river 

 into canon. In several places near the river the valley is swampy, but 

 generally it is dry, with a coarse, gravelly soil, of little value for agri- 

 culture. Grass is abundant and of excellent quality, and as a grazing 

 region, especially in winter, I should judge it to be well adapted. On 

 the west side of the valley the country rises sharply into plateaii-like 

 hills, well grassed. Further back these plateau-levels rise to a range 

 of sparsely wooded hills, which separate the drainage of Salt Eiver from 

 that of the Blackfoot. To the southward these broken hills rise into 

 mountains, of which Mount Preuss is the culminating point, and then 

 again decrease in elevation towards Bear Kiver. 



THE BASIN OF THE BLACKFOOT. 



This Stream, a branch of the Snake, which it enters a few miles west 

 of Fort Hall, pursues a curiously sinuous course. Heading in the hills 

 opposite Smoking Creek, it flows at first nearly west, then turns to the 

 south, and after flowing in this course for several miles, on meeting a 

 northward-flowing branch, it compromises with it by turning again to 

 the west. On this course, varied by occasional short turns to the south, 

 it passes through . a range of hills, a spur from the Mount Preuss 

 group, and around the south margin of a valley called by some fanciful 

 map-maker the "Hollow Hand," on the way receiving two large 

 branches from the south. The second of these turns the main stream 

 to its own direction, and a northward course is assumed, but, flowing 

 against a basalt wall, the stream is forced to resume its western course. 

 Then, on reaching a depression in the field of basalt, the stream crosses 

 it to its northern edge, passing with sluggish current through great 

 swamp areas. Eeaching the hills on the north side of this basalt-field, 

 outliers of the Blackfoot Eange, it turns west again, then northwest, 

 cleariug the basalt and running in among the hills. Here we lose sight 

 of this delectable stream, whose waters are now lukewarm and full of 

 vegetable matter from their long stay in swampy regions. 



The basin of this stream extends north to the north line of my dis- 

 trict. On the east it is limited by the hills separating it from Salt 

 Eiver drainage ; on the south, a range of high, s]ia.rsely-tiinbered hills 

 divides it from the Bear Eiver ; while on the west the divide is some- 

 w^here in a broad field of basalt. The northern part of this basin is 

 floored with basalt, out of which rise numerous ridges and buttes to a 

 considerable height. The southern part is occujiied by northward-trend- 

 ing spurs from the mountains, between which are broad valleys, in or 

 across which flow streams tributary to the main river. The basalt re- 

 gion is characterized by great areas of swamps. John Day's Lake, just 

 beyond the north line of my district, is the largest one of them. It is 

 not, properly speaking, a lake, although there is, even in the dry sea- 

 son, quite a large body of standing water in the middle of the swamp. 

 The Blackfoot flows through a very large swamp in crossing the basalt 

 field, a?; Avas noticed above. The Little Blackfoot enters it in this 

 swamp, and further up its course the latter stream i^asses through 

 anotlier large swaij^ij). 



The floor of the Blackfoot Basin, or the "Hollow Hand," has a very 



