28 GRAVEL AND PLACER MINING IN ALASKA. [bull. 268. 
Methods of working alluvial gold deposits of Alaska — Continued. 
Class of placers. 
Method of working. 
Bench placers a 
Hydraulicking. 
Open cutting, separate stripping, and shoveling in. 
Open cutting, separate stripping, and horse scraping. 
Shaft or adit, drifting, and timbering. 
Shaft or adit, thawing, drifting, little timbering. 
River-bar placers & 
Hydraulicking with hydraulic elevators. 
Dredging. 
Open cutting, steam shovel. 
Gravel-plain (tundra) 
placers. c 
Hydraulicking with hydraulic elevating. 
Open cutting, separate stripping, and shoveling in. 
Shaft, thawing, and drifting. 
Sea-beach placers d 
Digging shallow pits and shoveling in. e 
Dredging. 
Special devices. 
Lake-bed placers 
Hydraulicking. 
a Detritus varying from 5 to 150 feet in thickness; in parts of Seward Peninsula to 230 feet. 
b Detritus from 3 to 60 feet in thickness. 
c Detritus from 15 to 150 feet in thickness. 
d Detritus from 1 to 6 feet in thickness. 
e The greater part of the gold from the beach sands has been obtained by rockers. 
The above classes are based on operations actually seen during the 
season of 1904. Suggestions concerning the application of other 
methods to certain forms of deposits are given in the body of the main 
report. 
In the districts (PL II,. p. 14) visited the deposits under exploitation 
as above classified were as follows: 
Classes of deposits worked in districts visited. 
Province. 
District. 
Class of placer worked. 
South Coast 
Juneau . . 
Creek and lake-bed placers. 
Interior 
Atlin . . 
Creek and bench deposits. 
Creek, hillside, and bench placers. 
Creek and bench placers. 
Creek, hillside, and river-bar placers. 
Creek placers. 
Klondike 
Eagle 
Birch Creek 
Fairbanks 
