VIII ADVERTISEMENT. 
Purington, C. W. Methods and cost of placer mining in Alaska. 
Schrader, F. C. The geology of upper Copper and Tanana rivers. 
Stone, R. W. The Kachemak Bay coal fields. 
Spencer, Arthur C. The Juneau gold belt. 
Wright, C. W. The mineral resources of Admiralty Island. 
Wright, F. E. The mineral resources of the Wrangell district. 
The mineral resources of the Sitka district. 
TOPOGRAPHIC MAPS OF ALASKA. 
The following maps are on sale at 5 cents a copy, or $2 a hundred: 
Barnard, E. C. Forty mile quandrangle; scale, 1:250000. 
Peteks, W. J. Juneau special quadrangle; scale, 1:63500. 
The following maps are included as illustrations of published reports, but have nol 
been issued separately. They can be obtained only by securing the report: 
Barnard, E. C. Cape Nome and adjacent gold fields; scale, 1 : 250000. Contained in 
a-special publication of the U. S. Geol. Survey, entitled "Reconnaissances a 
in the Cape Nome and Norton Bay regions, Alaska, in 1900," Washington, 
Government Printing Office, 1901. 
Brooks, A. H. York and Kugruk regions, sketch maps of. Contained in " A\ 
reconnaissance in Cape Nome and Norton Bay regions, Alaska, 1900." 
Gerdine, T. G. Koyukuk and Chandlar rivers, portions of ; scale, 1 : 625000. Con 
tained in "Preliminary report of a reconnaissance along the Chandlar andlj 
Koyukuk rivers, Alaska, in 1899." Twenty-first Ann. Rept., pt. 2, 1900. 
Seward Peninsula, northwestern part of; scale, 1: 250000. Contained in Pro- 
fessional Paper No. 2. 
Fairbanks and Birch Creek districts, reconnaissance maps of; scale, 1: 250000. 
Contained in "The gold placers of Fortymile, Birch Creek, and Fairbanks 
districts." Bulletin No. 251. 
Yukon-Tanana region, reconnaissance map of; scale, 1:625000. 
Copper and upper Chistochina rivers; scale, 1:250000. Contained in "A\ 
geology of the central Copper River basin." Professional Paper No. 41 
and Witherspoon, D. C. Chitina and lower Copper River region; scale, 
1:250000. Contained in "The geology and mineral resources of a portion i 
of the Copper River district, Alaska." Special Publication of the U. S. 
Geol. Survey, Washington, Government Printing Office, 1901. 
Goode, R. U. A topographic map of Alaska; scale, 1: 250000. Preliminary edition. 
Contained in Professional Paper No. — . 
Lowe, P. G., Mahlo, Emil, and Schrader, F. C. Copper River region; scale, 
1:376000. Contained in "A reconnaissance of a part of Prince William 
Sound and the Copper River district, Alaska, in 1898." Twentieth Ann. 
Rept., pt, 7, 1900, pp. 311-423. (Out of stock.) 
Mahlo, Emil, and Schrader, F. C. Prince William Sound, sketch map of; scale- 1 
1 : 376000. Contained in "The geology and mineral resources of a portion 
o!' the Copper River district, Alaska." (Out of stock. ) 
Mendenhall, W. C. Cook Inlet, head of, to the Tanana via Matanuska and Deltai 
rivers, also part of Kenai Peninsula; scale, 1:625000. Contained in "A, 
reconnaissance from Resurrection Bay to Tanana River, Alaska, in 1898." 
Twentieth Ann. Rept., pt. 7, pp. 265-340. 
Muldrow, Robert. Sushitna River and adjacent territory; scale, 1:625000. Con-, 
tained in "A reconnaissance in the Sushitna basin and adjacent territory, 
Alaska, in 1898." Twentieth Ann. Rept., pt. 7, 1900, pp. 1-29. 
Peters, W. J. Tanana and White rivers, portions of; scale, 1:625000. Contained 
in "A reconnaissance in the Tanana and White River basins, Alaska, in 
L898." Twentieth Ann. Rept., pt. 7, 1900, pp. 425-494. 
Lynn canal, routes from, via headwaters of White and Tanana rivers tc 
Eagle City; scale 1 : 625000. Contained in "A reconnaissance from Pyra- 
mid Harbor to Eagle City, Alaska." Twenty-first Ann. Rept, pt. 2, 1900, 
pp. 331-391. 
Norton Bay region; scale, 1:625000. Contained in "Reconnaissances oi 
Cape Nome and Norton Bay regions, Alaska," 1900. 
Koyukuk River to mouth of Colville River, including John River; scale, 
1:625000. Included in Professional Paper No. 20. 
