THE OVERLAND ROUTE — OGDEN TO SA^f FRANCISCO. 201 



Just beyond the Donner cross and before the first snowsheds are 

 entered, a bit of the lower end of Donner Lake may be seen by looking 

 through the trees up the valley ahead. From this point the train 

 turns southwestward, going up one side of the vallev of Cold Creek. 



chmbin 



As 



the train rounds the loop in Cold Creek valley the rear platform 



culmmating in 



Creek 



feet), only 2 or 3 miles distant, 

 the snowsheds are almost continuous. They extend from this valley 

 along about 40 miles of the railroad, the last shed being just beyond 

 Blue Canyon, on the west slope. It is unfortunate that no satis- 



tracks from 



over the 



without marring the most beautiful part of the route 

 mountains. 



Rounding the point of the ridge at the left (north) and passing 

 through a curved tunnel, the train comes out just above Donner 

 Lake. The basin of this beautiful mountam lake is apparently of 

 glacial origin, as the water occupies a hollow, evidently once filled 

 by a glacier, with bare granite cliffs at its upper end and a heavy 

 terminal moraine at its lower end. This moraine holds back the 

 water of the present lake, but the basin is believed to have been 

 orlginalh^ dammed lower down by flows of basaltic lava which spread 

 across the valley just west of Truckee and through which Donner 

 River subsequently cut its way. Near the head of Doimer Lake the 

 train runs back into another southward loop and, crossing some 

 heavy deposits of morainal debris, comes out above the upper end of 

 Donner Lake. (See PI. XLYII, A.) From this point it is but little 

 more than a mile to the long tunnel through granite by which the 

 crest is pierced. 



Donner Pass, the highest pomt along the railroad, is just above the 

 tunnel. The elevation of the tunnel is 7,012 feet; the pass above 



Summit. 



the tunnel is of couree somewhat higher. Just be- 

 yond the tunnel is a flag stop known as Summit 

 Omaha i,5S9 miles. jj^^^j^ ^^^j ^^^ ^ ^^^^ ^^ ^^ farther is the station in 



the snowsheds called Summit- Although it is difficult to see out of 

 the snowsheds, ghmpses to the south disclose the west side of the 

 main Sierra crest, usually with at least a few snow patches throughout 

 the summer. The 150-mile trip from Sacramento to this point, a 

 climb of nearly 7,000 feet, and down the east side of the range into 

 Nevada is mentioned in the Sacramento papers in the unimpassioned 

 phrase ^^going over the hill." And yet they say that the westerner 

 exaggerates. 



The annual precipitation is very high over the west slope, ranging 

 from a mean of 52 inches at Cisco, at about 6,000 feet, to 48 inches at 



