PREFACE. 
By Alfred H. Brooks. 
In planning the surveys and investigations of Alaska, the attempt 
was made to cover first those regions which were of the greatest eco- 
nomic importance. As a result of this, many of the mapped areas 
are very irregular in outline, and it now seems desirable to introduce 
greater uniformity into the published maps as rapidly as the data 
available for their preparation will permit. With this end in view 
a system of maps has been projected covering quadrangular areas 
outlined by parallels of latitude and meridians of longitude, this being 
in conformity with practice in surveys made within the United States 
proper. But as the Alaska surveys are for the most part of a recon- 
naissance character and the region is very thinly populated, it has 
seemed best to adopt a map unit larger than that used in the States. 
This unit will include 4 degrees of longitude and 2 degrees of latitude, 
making a map about as large as can be conveniently handled. It is 
hoped that eventually these published reconnaissance topographic 
maps can be accompanied by sheets showing the geology and the eco- 
nomic resources, but in view of the great demand for the topographic 
maps it has been deemed advisable to publish them immediately with 
such accounts of the geology and mineral resources as may be avail- 
able. Nor is it deemed desirable to delay the issuing of maps until 
the areas have been completely covered. 
The following report, with its accompanying maps (Pis. I, IV, 
and V), is the second of this series to be issued, and it will be fol- 
lowed by others as fast as the accumulation of the field notes will 
permit. The topographic surveys on which the maps are based were 
made under the direction of T. G. Gerdine in L903 and I). C Wither- 
spoon in 1004, 1905, and 1006; the geology is by L. M. Prindle, who 
has worked in this general field in L903, L904, 1005. and L906. Mr. 
Prindle was assisted in his geologic work in 1004 by Frank L. Hess 
and in 1905 by Adolph Knopf. The present writer, who crossed ilii- 
