66 FORTY MILE, BIRCH CREEK, AND FAIRBANKS PLACERS, [bull. 251. 
have been concentrated by stream action modified by localized annual 
glaciation, or " annual glaciers," as they have been called by Spurr. 
About 200 men were working on the creeks, the annual production 
being about the same as that of the Fortymile region — $175,000. 
FAIRBANKS REGION. 
GENERAL STATEMENT. 
In the rush of 1898 many started for the Yukon from Valdes. 
Some, after a hard trip, succeeded in reaching the Fortymile region; 
others, on arriving at the Tanana, chose the line of least resistance' 
and drifted down the river. The economic results were scanty, but 
some knowledge was gained of general conditions in the Tanana; 
Valley. In the same year a party from the Geological Survejl 
under Peters and Brooks, descended the Tanana from the head- 
waters, mapped the area along the river, and studied the geology. 
An opportunity was thus given to compare the rocks of this region 
with those of the gold-producing creeks of the Fortymile and Birch 
Creek regions, studied by Spurr in 1808. The formations were 
found to be similar to those of the better-known regions, and it is 
interesting, in the light of recent developments in the Tanana Valley, 
to read again the following extract from the summary of Brooks's 
report regarding the possibilities of the region : 
In this description of the gold resources an attempt has been made to state 
the hare facts, clearly shorn of all speculations and wild rumors. We have 
seen that traces of gold have been found throughout the region examined by 
our party, and that the conditions for its occurrence are in many respects favor] 
able; also that the little prospecting which has been done up to the present 
time has been too hurried and too superficial to be regarded as a fair test oi 
the region. Our best information leads us to believe that the same horizons 
which carry the gold in the Fortymile and Birch Creek districts are repr&j 
sented in the White and Tanana river basins. I believe, therefore, in spite oi 
the adverse results which have been obtained so far, which are purely nega- 
tive, that the White and Tanana river basins still offer a favorable field fo| 
the intelligent prospector. I am inclined to think that the upper basins of 
these rivers are occupied chiefly by the younger non-gold-bearing rocks. I 
should advise prospectors to carefully investigate the small tributary streams 
of the lower White and of the Tanana from Mirror Creek to the mouth. The 
headwaters of the streams lying to the north of the Tanana ought to offer 
favorable returns, situated, as they are, opposite the headwaters of Fortymile 
and Birch creeks, streams which are more or less gold bearing. & 
Occasionally men from the Fortymile. and Birch Creek regions 
made short trips over the hills to the south in the early days and did 
some prospecting in the valley of the Tanana, but trips through this 
country were necessarily of a hurried nature on account of the dis 
"Spurr, J. E., Geology of the Yukon gold district: Eighteenth Ann. Kept. U. S. (icol. 
Survey, pt. .°>, 1808, p. 346. 
h Brooks, Alfred H. A reconnaissance in the Tanana and White river basins, Alaska, 
jn 1898: Twentieth "Ann. Kept. TJ. S. Geol. Survey, pt. 7, 1900, p. 488. 
