brooks.] ADMINISTRATIVE REPORT. 15 
The authorship of this bulletin is composite, for all the geologists of 
the Alaskan division have made contributions, and each paper will be 
found credited to its writer. Mr. Cleveland Abbe, jr., has rendered 
valuable aid in the preparation of the various contributions for 
publication. 
PROGRESS OF INVESTIGATIONS. 
Nine parties were dispatched to Alaska during the summer of 1904; 
of these five were engaged in geologic investigations, two in topo- 
graphic surveys, one was a combined geologic and topographic party, 
and one studied the methods and costs of placer mining. As several 
of the expeditions were subdivided after reaching the field, there were 
in all fourteen parties engaged in these surveys during most of the 
summer. 
The geologic work included a, reconnaissance of parts of southeastern 
Alaska, a study of the gold, coal, and oil fields of the Cook Inlet region, 
a continuation of the investigation of the Fairbanks and Rampart dis- 
tricts, a survey of the Cape Lisburne coal field, and a continuation of 
the work in the Seward Peninsula. Topographic reconnaissance sur- 
veys (scale 1:250,000) were made over about 4,000 square miles in the 
Yukon-Tanana region and about 1,500 square miles in the Cook Inlet 
placer district, and a detailed map (scale 1:45,000) was made of about 
600 square miles near Nome. A special study of methods and costs of 
placer mining was made in the Juneau, Eagle, and Birch Creek regions 
and in the Seward Peninsula, and an examination of some of the 
Canadian placer districts was made for comparative purposes. 
General. — Mr. C. W. Purington, accompanied by Mr. Sidney Paige, 
spent some three months in the study of placer mining methods, as 
already outlined. A part of his results are presented in this bulletin, 
and his final report is almost completed. This is the first attempt 
that has ever been made at a systematic investigation of this subject 
in this northern field, and it is believed that the results will be of value 
to those engaged in exploiting Alaskan placers. 
The writer's time has been largely given to administrative duties 
and to the preparation of a summary of existing knowledge of the 
geology and geography of Alaska, which has been submitted for pub- 
lication. A brief visit was made to some of the Alaskan placer camps 
dining the summer, and special attention was given to collecting data 
for the summary of mining developments which follows. Much of 
the matter, however, contained in this summary should be credited to 
the men who have been making detailed examinations of the placer 
districts. 
Southeastern Alaska. — Mr. Fred E. Wright, assisted by Mr. C. W 
Wright, continued the geologic reconnaissance of southeastern Alaska 
a Bulletin No. 263. 
