prindle.] EORTYMILE, BIRCH CREEK, AND FAIRBANKS PLACERS. 39 
go:ld placers. 
fortymile region. 
FORTYMILE AREA. 
Since the discovery of gold on Fortymile Creek, in 1886, pros- 
pectors have devoted much attention to its basin. The most im- 
portant creeks at present are Wade, Walker Fork, Chicken, and 
Franklin, while some work is being done on the Fortymile itself, 
Napoleon Creek, the tributaries of Canyon Creek, and on North Fork 
of Fortymile. Prospecting is in progress in many places and still 
results occasionally in discoveries of economic importance. 
Wade Creek. — The basin of Wade Creek, which is reached by trail 
from the mouth of Steele Creek, lies about 10 miles south of the 
Fortymile, and embraces about 50 square miles (map, PI. VII). The 
creek, which is about 12 miles long, heads in Steele Dome, 3,750 feet 
high, and flows in a nearly straight southwesterly direction, entering 
Walker Fork a few miles above its mouth. There is a fall of about 
GOO feet from the upper limit of placer mining to the mouth — a dis- 
tance of about 8 miles. The valley is sunk to a depth of about 1,500 
feet within the plateau, and is narrow and V -shaped in its upper por- 
i ion ; lower down it gradually widens, finally merging into the valley 
of Walker Fork, where the stream follows a meandering course over 
the surface of a broad flat. The spurs from the northwest descend 
somewhat more gradually toward the stream than those from the 
opposite side, and the cross section of the valley is thus somewhat 
unsymmetrical. The general characteristics are shown in PL VI, B. 
The tributaries are short and flow in narrow V-shaped valleys. In 
dry seasons the demand for water far exceeds the supply, and much of 
the mining is brought to a standstill. 
There is considerable timber on the northwest slopes of the valley, 
and a light growth of spruce on the southeast. The valley floor is 
generally covered with willows, but in the wider portion, toward 
Walker Fork, is well timbered with spruce and aspen. Dawson is 
the main source of supply, and most of the freighting is done during 
the winter. 
The bed rock in which the valley of Wade Creek has been in- 
cised includes several varieties of schist and some ferruginous, thin- 
bedded limestone, which is apparently interbedded with the schist. 
Mica-schist and hornblende-schist are the most common rocks. Their 
attitude is variable, but the general strike is northeast, about parallel 
with the creek, and the dip of the schistosity varies from nearly hori- 
zontal to 50° or more to the southeast, while a prominent system of 
joints strikes N. 30° W. The schists are often contorted and the 1 
structure is probably complex. A small dike of basalt, with a strike 
