146 ALASKA AND ITS MINERAL RESOURCES 



be the representative of the Great Basin region in the United 

 States, since north of the 49th parallel the uplift of the Sierra 

 Nevada has merged with that of the Coast ranges into one gen- 

 eral system. 



The Coast range proper is a broad elevated belt with many 

 scattered peaks, but not differentiated into continuous l'anges. 

 Oceanward it presents an abrupt, rugged front, cut by fiord-like 

 valleys. To the east is a plateau-like region which descends 

 graduall} r to the north from an elevation of 5,000 feet in the 

 upper lake region to 3,000 feet in the lower Lewes and Pelly 

 river vallevs. The river valleys in this stretch often lie 2,000 

 to 2,500 feet below the general plateau level. 



In the interior region the soil is frozen for a large portion of 

 the year, so that there is comparatively little rock decay. Where 

 there is no timber the surface is generally covered with an abun- 

 dant growth of moss. This, wherever the surface material is 

 sufficiently compact to become impervious to water by freezing, 

 produces large areas of swampy tracts, even on sloping ground, 

 which, except in the glaciated regions or when cut through by 

 large streams, obscure the rock surface and render difficult the 

 work of the prospector. 



The northwestern continental ice-sheet, or cordilleran glacier 

 of Dawson, which centered in British Columbia between latitudes 

 55° and 59° N., did not extend in this interior region north of 

 the 62d parallel, b.3nce the greater part of the Yukon basin has 

 not been glaciated, except by local glaciers. This fact has been 

 readily recognized by the geologists who have visited the region in 

 recent times, and indeed is evident, on inspection of the maps, by 

 the abundance of lakes above this line and their absence below it. 



The Yukon or all-water route. — This route is by ocean steamer 

 from Seattle or San Francisco to St Michael, near the mouth of 

 the Yukon ; thence by river steamboat up the Yukon to Dawson. 

 The length of this route is about 4,000 miles, it being nearly 2,700 

 from Seattle to St Michael, and about 1,300 up the Yukon to 

 Dawson. Those taking this route aim to leave St Michael early 

 in July, in order to avoid the delays in upstream progress caused 

 by sand-bars at low stages of water later in the season. The 

 time from Seattle to St Michael is about twenty clays, and that 

 from St Michael to Dawson the same, making about forty clays 

 for the trip. Under favorable weather and circumstances it 

 may be made in less time. Though this route is the one over 

 which commercial companies operating in the Yukon country 



