rnVSICAL FEATUllES OF THE GREAT BASIN. 315 



tortuous. It at length spreads out into Uuinboldt Lake, shallow and sulialkaliiio, and 

 from this the little remaining surplus water finds its way in a manner similar to ihc 

 C'arson River into the same sink. 



The descent of 2,000 feet from eastern Nevada iuto the Great Salt Lake Basin is 

 almost immediate, nearly the whole northwestern portion of Utah being an alkaline 

 desert, broken by fewer mountain or hill ranges, and but little above the level of the 

 lake. The lake itself is for the most part very shallow, in no place over 50 feet in 

 depth, the waters a concentrated solution of salt. As with all these sheets of water 

 the shore line and consequent area vary greatly in different years. 



The intermediate ranges of the Basin are very similar to each other in character. 

 They vary in altitude from one to 0,000 feet above the valleys, culminating in occa- 

 sional peaks scarcely ever so rugged that they cannot be ascended from some direction 

 ui>on mules. They are cut up by numerous ravines or "cafions," which are narrow, 

 very rarely with an acre of interval or surface approaching to a level, the sides some- 

 times rocky or preci[)itous, more frequently sloping to the summits of the lateral ridges. 

 In geological structure these ranges are more or less complicated, showing rocks of all 

 ages from the azoic to the glacial period, here metamorphic rocks, quartzites, slate, and 

 limestones, there an outburst of granite or syenite, volcanic rocks of often the most 

 diverse aud picturesque colors, or broad tablelands of lava ovefHow. The erosion and 

 decomposition of these various rocks have filled the valleys to a monotouous level with 

 a detritus of gravel, sand or silt, and given to them that accumulation of alkaline salts 

 which is so marked a peculiarity of the country. 



With few exceptions, also, these mountains are for most of the year wholly desti- 

 tute of water, with but small rivulets in the principal cauons, frequently with only 

 scanty springs here aud there at their bases, irrigating a few square yards of grouud. 

 Even where the mountain supply is sufficient to send a stream iuto the valleys it is 

 usually either soon entirely evaporated, sinks iuto the porous soil, or becomes demor- 

 alized with alkali and is "lost" in the mud of the plaiu. The lowest i)ortiou of nearly 

 every valley is occupied by some extent of alkali fiat, where iu the winter season the 

 water collects aud the softened clay-like mud is bottomless and impassable. As 

 the moisture evaporates under the heat of coming summer the level naked surface 

 becomes hard and pavement-like, or covered with a snowy incrustation or deposit of 

 salt or carbonates. The springs and wells even are often more or less saline, and 

 thermal springs are not rare. 



The chief exceptional ranges iu northern Nevada, which from their greater altitude 

 receive heavier snowfalls in winter, retained through the year in greater or less quantity 

 iu the more sheltered depressions of the higher peaks, aud which in summer are subject 

 to more abundant rains, are the West Humboldt Mountains, 100 miles east of the 

 California State line, the East Humboldt Mountains, 75 miles from the Utah line, and 

 the Toyabes, uearly intermediate between the two. Star Peak is the highest i)oiut of 

 the first range, with an altitude of uearly 10,000 feet, but with little deposit of snow 

 and the vegetation of the summit scarcely subalpine. Several constant streams here 

 flow from the principal eastern canons and reach the middle of the viilley, where they 

 supply irrigation for as many small ranches. The Toyabe Range, esi)ecially in its 

 southern portion, is higher, several of its peaks having an altitude of from 10,000 to 

 12,000 feet, with more snow and fuller streams. The waters of the eastern slope are spent 

 iu Smoky Valley. On the western side lies Reose River, flowing northward toward the 



