80 Explorations and Surveys for the Pacific Railroad. 



but more frequently this isolation is only apparent. The moun- 

 tains are sharp, rocky, and inaccessible in many parts, but are 

 low and easily passed in others. Their general elevation varies 

 from 1,500 to 3,000 feet above the valleys, and but few of them 

 retain snow upon their highest peaks during the summer. They 

 are liberally supplied with springs and small streams, but the lat- 

 ter seldom extend far into the plains. At the time of melting 

 snows there are many small ponds and lakes, but at other sea- 

 sons the waters are absorbed by the soil near the base of the 

 mountains. Grass is found in abundance upon nearly every 

 range, but timber is very scarce — a small scattered growth of 

 cedar only being seen upon a few ranges. East of the Humboldt 

 mountains the growth of cedars is more abundant, and the grass 

 better, than to the west. The valleys rarely have a width east 

 and west of more than five or ten miles, but often have a large 

 extent north and south. They are irregular in form, frequently 

 extending around the ends of mountains, or uniting to succeed- 

 ing valleys by level passages. The greater part of the surface 

 of these valleys is merely sprinkled by several varieties of som- 

 bre artemisia, (wild sage,) presenting the aspect of a dreary waste. 

 Though there are spots more thickly covered with this vegeta- 

 tion, yet the soil is seldom half covered with it, even for a few 

 acres, and is nowhere suitable for settlement and cultivation. 

 Immediately west of Great Salt lake there is a plain of mud, 

 clay, and sand, impregnated with salt, seventy miles in width 

 from east to west by its longest line, and forty at a narrower 

 part further south, thirty miles of which must be piled for the 

 passage of a railroad across it. A railroad may be carried over 

 this series of valleys and around the mountain masses, at nearly 

 the general level of the valleys. 



The route in this manner reaches the foot of the Humboldt 

 mountains, a narrow but elevated ridge, containing much snow 

 during most of the year, and crosses them by a pass nine miles 

 long, about three of which are occupied by a narrow, rocky ra- 

 vine, above which the road should be carried on the sloping 

 spurs of the mountains on the western descent; elevation of 

 summit 6,579 feet above the sea. At the time when passed, 

 21st May, snow covered the high peaks above it, and a few 

 drifts extended into the ravines down to the level of its summit. 



The descent is now made to the open valley of Humboldt 

 river, which is followed for about 190 miles. The steepest 

 grade proposed in the pass of Humboldt mountain is 89 feet per 

 mile for eight miles, but this can be reduced by gaining distance 

 to any desirable extent. 



The Humboldt river, as described by Colonel Fremont, is 

 formed by two streams rising in mountains west of the Great 

 Salt lake. Its general direction is from east to west, coursing 



