48 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull. 213. 
miles above Eagle, two or three claims were worked last summer. In 
the immediate vicinity, on American Creek and Colorado Creek, tribu- 
tary to Mission Creek, some mining was also done. Seventyinile 
River was also the scene of mining operations, about 15 miles from 
the Yukon, and one hydraulic plant was run. On Fourth of July 
Creek, 50 miles below Eagle, 12 men were at work on claims last 
summer. Three claims on Coal Creek and several on Woodchopper 
Creek, 140 miles below, also received some development of their 
placers. 
COPPER RIVER REGION. 
Gold has been found in commercial quantities at two widely sepa- 
rated places in the Copper River Basin. The Chistochina gold field, 
which has produced nearly all the gold of the region, is in the drain- 
age basin of a river of the same name which joins the Copper about 
200 miles from the coast. This district contains several gold-producing 
creeks which can be reached by trail from Valdes. Gold placers have 
also been found at a number of widely scattered localities in the Cop- 
per River Basin. A description of this district by Mr. Mendenhall 
will be found elsewhere in this volume. 
COOK INLET REGION. 
The region lying adjacent to t he head of Cook Inlet and about 
Turnagain Arm has long been a small gold producer. No very rich 
placers have been found, but the accessibility of the district made 
it possible to develop deposits which could not have been worked at 
a profit if located in the interior. Hydraulic mining has been going 
on in a small way lor a number of years, and more elaborate plants are 
being installed. The open season of Cook Inlet comprises about five 
months, which gives the district two months' advantage, or more, over 
that of the interior, or of Nome. The developments of the last year 
have been rather in the way of introducing more refined methods of 
mining rather than of new discoveries. 
PORCUPINE DISTRICT. 
This is a small placer-gold district about 30 miles from Pyramid 
Harbor, an embayment of Lynn Canal, whence it is easily accessible 
bj r wagon road. It lies chiefly within the catchment basin of Porcu- 
pine Creek, a small stream which enters the Klehini about 20 miles 
above its junction with the Chilkat. The placers are so situated that 
they offer peculiarly difficult conditions for mining. They occur 
largely in small glacial benches and in the stream bed of Porcupine 
Creek, which has a very sharp rock-cut valley. To work these pla- 
cers it has been necessary to divert the water of the stream by means 
of sluices, to give access to the gravels in the creek bed. This involved 
a large expenditure of time and money. During the last season these 
developments were still going on, and the district has not yet reached 
a large productive stage. 
