64 FORTYMILE, BIRCH CREEK, AND FAIRBANKS PLACERS, [bull. 251. 
steep slope which borders the valley on the southeast. In the lower 
valley these conditions are reversed. 
The bed rock is quartzite and quartzite-schist veined with quartz. 
Granitic dikes occur on the divide between Miller and Eagle creeks.] 
The gravels are similar in character and arrangement to those on the j 
Mastodon. The depth to bed rock varies from 8 to 16 feet and there 
is from 4 to 8 feet to strip. Occasionally there is clay, which has been] 
found to be as much as 3 feet in thickness between the gravels and bed] 
rock. This, when present, contains most of the pay. The gold isj 
about the same as that of the Mastodon. Pieces weighing an ounce 1 
have been found, but the general run is rather fine. That near the! 
head of the creek is rough. The gold is found scattered through sev- 
eral feet of gravel over a maximum width of about 50 feet. Some of 
the ground averages about $1.20 to the cubic yard. It is worked by: 
open cuts, where the average depth to bed rock is about 12 feet, with 
(') to 8 feet to strip. It is said that two men can work about 20 box 
lengths of 12 by 16 feet in a season. Near the head of the creek a 
month's work may be lost during the summer by low water. The 
annual production is perhaps $3,000 to $5,000. About 10 men werel 
working on the creek during the season of 1903. 
Eagle Creek and tributaries. — All the above creeks are tributary to] 
Crooked Creek. Over the divide from Mastodon and Miller creeksi 
are the headwaters of two small streams, Mastodon and Miller forks," 
which unite to form Eagle Creek, a tributary of Birch Creek. Gold' 
was discovered on Eagle Creek in 1895, and much work has been dona 
on this creek and on Mastodon Fork. Mastodon Fork heads in an 
amphitheatral area on the northwest slope of Mastodon Dome, and 
flows northwesterly through a narrow V-shaped valley for a distance' 
of about 3 miles to Miller Fork. The bed rock and gravels are similar^ 
to those on the other side of the divide. As on Miller Creek, clay is 
often found next to the bed rock of quartzite-schist. The depth tog 
bed rock varies from 8 to 10 feet or more. In some cases there are 3 
to 4 feet to strip and 4 to 5 feet of pay dirt. When clay occurs along 
with the gravels, the gold is often found in seams in the clay a few 
inches above bed rock. It is also found in the bed rock to a depth of* 
3 feet. Values are said to occur irregularly on the creek. Some 
ground has been very good and has yielded from $2 to $4 per cubic 
yard. The gold is often coarse. A flat nugget was found during 
the season of 1903 the dimensions of which were 2 by 1J inches and 
the weight 2J ounces. Some quartz was attached, and the nugget had! 
the appearance of having been derived from a seam in the bed rock. 
Work has been done on about H miles of the creek, the claims having 
been worked by open cuts. The creek is said to have produced from! 
$15,000 to $18,000 during the season of 1903. 
