468 EEPOKT UNITED STATES GEOLOGICAL SURVEY. 



TOPOGRAPHT. 



Heading the Southern Fork of the Columbia and the greater part of 

 the drainage of the Missouri, it lies very high compared to the average of 

 the country thereabouts. Its mean height is not far from 8,000 feet 

 above sea-level. The lowest point in the Park — the mouth of Gardiner's 

 Eiver — is 5,360 feet, while the highest mountain peak — Electric — is 

 11,155 feet above sea. 



The surface is largely made up of level or rolling country, plateau-like 

 in character and heavily timbered. In this plateau many of the streams 

 have cut tremendous gorges. Several groups of mountains diversify 

 the surface, as the Eed Mountains and the Washburn group. Iq the 

 northwest corner rises the Gallatin Eange, which separates the Yellow- 

 stone from the Gallatin Eiver, and which culminates in the magnificent 

 mountain known as Electric Peak. East of the Yellowstone Eiver and 

 Lake rises a very high and rugged range, which stretches from Union 

 Pass north to the bend of the Yellowstone, a range to which Dr. Hayden 

 has given the name of the Yellowstone Eange, and which subsequently 

 Capt. W. A. Jones called the Sierra Shoshone. The southern section 

 of the Park is drained by the various affluents of Snake Eiver, Bech- 

 ler's Fork, Falls Eiver, Lewis Fork, and Barlow's Fork. This drainage 

 area comprises 682 square miles. It is made up mainly of plateaus, and 

 of high rolling country, most of which is densely timbered. 



bechlek's foek. 



This stream, named from its discoverer, Mr. G. E. Bechler, at that 

 time topographer of one of the parties of this survey, heads opposite 

 the head of the Madison or Firehole Eiver and Shoshone Lake, being 

 separated from them by narrow, abrupt divides of no great height. 

 Its head and most of its course are through a high volcanic plateau, 

 and for most of its course it is sunken far below the general level in a 

 deep, rugged cafion. The plateau is well timbered with the larger 

 coniferse. Falls Eiver Basin, into which this stream debouches abruptly, 

 the plateau ending suddenly in a line of cliffs facing to the westward, 

 is a large valley, part of which is open, while a part is covered with 

 a dense growth of large conifersB, and the ground is cumbered with 

 fallen timber to such an extent that, added to the swampy, springy 

 nature of the soil, the Basin is wellnigh impassable. Of the extent of 

 the Basin I cannot speak, as it extends far to the west and north of the 

 limits of my work. Into it flow several large streams. Besides Bech- 

 ler's Fork, Falls Eiver, Cascade Creek, and a large northern branch of 

 Falls Eiver enter this basin. This valley has but very little slope, and 

 the streams which enter it are immediately split into a number of chan- 

 nels, with many slues and back-waters, which are interlaced with one 

 another in a coraj)lex network. It contains also many stagnant pools 

 and ijonds, and multitudes of springs break forth from the base of the 

 limiting cliffs. It is one of the few remaining haunts of the moose in 

 the Northwest. 



FALLS RIYEE. 



This stream heads in the southern slopes of the great plateau which 

 Bechler's Fork traverses, rising in four large springs, which give birth 

 immediately to a good-sized river. Its course is nearly due west, skirt- 

 ing the southern base of this plateau. The divide between this stream 

 and the ^nake is very gentle, being, indeed, almost imperceptible. Its 



