The Bristol Bay region
includes the area drained by streams flowing into
Bristol Bay from Cape Newenham on the west to and including Egegik
Bay on the east and into Shielikof Straight from Cape Douglas on
the north to Cape Kekurnoi on the south. The region is considered
as one district.
The southeastern part of the region consists of rugged mountains,
the highest peaks of which are mainly Quaternary volcanoes, some
active in historic time, with summits 5,000 to 7,500 feet in altitude.
The northwestern part is a lake-dotted area less than 1,000 feet
above sea level; isolated hills rise a few hundred to slightly
more than 2,000 feet. The Ahklun Mountains in the western
part of the region make up a low, but rugged range that con¬tains
large deep lakes of extraordinary scenic grandeur.
The mountains in the eastern part of the Bristol Bay region consist
of rocks that range from possibly Permian metamorphosed volcanic
rocks to Tertiary and Quaternary lava flows and frag¬mental
rocks. The bulk of the bedded rocks are Mesozoic sand¬stone,
shale, and conglomerate. Northwest of a major fault, the Bruin
Bay fault, the older rocks were invaded and locally metamorphosed
by the dioritic Aleutian Range batholith of Jurassic age and
smaller younger felsic and mafic plutons and volcanic necks (Burk,
Detterman and Reed, 1968).
In the western part of the region, bedrock is mainly Paleozoic
and Mesozoic clastic and volcanic rocks and Tertiary felsic and
maflc dikes, sills, and small plutons (Mertie, 1938b; Hoare and
Coonrad, 1961). Between the eastern and western mountains, the
region is a lowland underlain by thick glacial and alluvial deposits;
bedrock is exposed only around its margins and in a few hills
that protrude through the surflcial materials. Except for its
part, the region was glaciated and is now mainly in zones characterized
by isolated masses of permafrost.
Lode deposits containing mercury, gold, silver, copper, lead,
zinc, antimony, and iron are known in the Bristol Bay region,
ore has been produced from them (Berg and Cobb, 1967, p. 9—16,
No rich placer deposits have been found in the Bristol Bay region
and few were ever developed much beyond the prospecting stage.
As records of mining activity are almost nonexistent, even the
locations of many of the reported occurrences of placer gold
are open to question. Undoubtedly gold has been found in many
places than shown on the map. The total production of
the region was probably at least 500 fine ounces, but not much
more than 1,000.
Most of the gold probably came from Cape Kubugakli (15)
and Portage Creek (14).
At Cape Kubugakli a small, steep stream drains an area of numerous
quartz veins in fine-grained igneous rock. The best
values in the creek
immediately downstream from the veins. Portage Creek is about
5 miles long and enters Lake Clark from the northwest.
1910 to 1912 and for a few years after World War II, some gold
was recovered, but the total amount was probably worth only a
few thousand dollars. Desultory mining and prospecting have been
from other streams in the same general area, but there has been no
activity on them for many years.
Bonanza Creek and its tributaries, Pass and Scynneva Creeks,
(12, 13) have been extensively prospected, but production
has been less than 150 fine ounces of gold. Quartz veins, some
containing a few sulfide minerals and a little free gold, are
the probable source
of the gold in the creek gravels. The valley of Bonanza Creek,
though narrow, might be capable of supporting a small dredge
or a dragline
operation under favorable economic conditions. The Nushagak River
and some of its tributaries, particularly the Mulchatna River,
are known to be auriferous and to have been the source of very
small amounts of gold in the late 1800’s and early 1900’s.
There was, however, no commercially successful mining in the
Farther west, on Trail Creek (7), a headwater tributary
of the Togiak River, there are signs of placer mining, but the
are not known.
A reconnaissance study of the U.S. Bureau of Mines (Berryhill,
1963) of beach sands around Bristol Bay failed to discover major
of valuable minerals. Although an atypical sample from a beach
south of Egegik (9)
contained nearly 250 pounds of iron per cubic
yard of beach material. There were traces of flour gold in a
from this beach and similar deposits on the northwest shore of
Hagemeister Strait (1-
where there was a small stampede in 1937 following overoptimistic
reports by prospectors.
from beach deposits around Bristol Bay was worth no more than
a few hundred dollars. The beach gold probably was mainly reconcentrated
from glacial deposits; some from Hagemeister Strait may have
been derived from nearby sulfide-bearing veins.