ALASKA AND ITS MINERAL RESOURCES 169 



between them and the waters of the Tanana, possesses great pos- 

 sibilities in the way of mineral development, but from all ac- 

 counts it is a region exceptionally difficult of access, and it may 

 well be questioned whether it is advisable to attempt its explora- 

 tion until facilities for travel and obtaining supplies in the Yukon 

 region have been increased, as they will be in the near future. 



More accessible is the region immediately north of the Tanana 

 river known as the Tanana hills and Ketchumstock hills, which 

 from reports appears to be mainly a granite region, but in which 

 it is likely that outliers or patches of the gold-bearing schists 

 will be found inclosed within the granite area. 



Late reports by prospectors in the Tanana region state that the 

 river has slack water, navigable for steamers 150 to 200 miles above 

 its mouth ; above that the current is swift. Mountains border the 

 river on the north side from the mouth up, on the south they are 

 far distant. Colors are found in all the creeks ; those heading 

 toward Fortymile and Seventymile offer best promises, but no 

 important prospects have been found. Toward Circle City the 

 creeks do not freeze up, and a hot spring was found in one of 

 the gulches. 



In the mountain region to the northeast of the Yukon river 

 immediately above the bend, such observations as have been 

 made do not offer much promise of exposures of the older gold- 

 bearing schists. Older limestones occur there, but, though im- 

 portant gold deposits are known to occur in limestones, in the 

 Yukon country the general rule appears to prevail that gold is 

 concentrated mainly in the siliceous rocks. It may well be, how- 

 ever, that in the conglomerate or cement deposits of the coal- 

 bearing formations that are known to occur in this northeastern 

 region there are portions sufficiently rich in gold to make pay- 

 ing placers by their wearing down. In searching for such places 

 the prospector should study the character of the pebbles that 

 make up the conglomerate ; it is only when these include frag- 

 ments of the gold-bearing rocks and occasionally of vein quartz 

 that they are likely to be productive. 



For the region east of the international boundary, Spurr had 

 already pointed out, as a result of his observations in the sum- 

 mer of 1896, that the Klondike and Indian creek regions were 

 likely to show rich placers, because the schists of the Birch 

 creek series, and to some extent the marbles of the Fortymile 

 series, formed the bed-rock. 



George M. Dawson reports bars of fairly coarse gold on the 



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