8 LETTER OF TRANSMITTAL'. 
region based on surveys by Mr. T. G. Gerdine in 1903. One map. 
on a scale of 1:250,000, extends from Fairbanks to Circle, and the 
other, on a scale of 1 : 625,000, embraces the entire Vukon-Tanana 
district. 
The maps and the text of this report must be regarded as prelimi- 
nary, for at this writing both geologic and topographic surveys are 
in progress in the same field. 
Very respectfully, 
Alfred H. Brooks, 
Geologist in Charge Division of Alaskan Mineral Resources. 
Hon. Charles I). Walcott, 
Director United States Geological Survey. 
