Geological Survey (U.S.).

Maps and descriptions of routes of exploration in Alaska in 1898 : with general information concerning the territory online

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Online LibraryGeological Survey (U.S.)Maps and descriptions of routes of exploration in Alaska in 1898 : with general information concerning the territory → online text (page 1 of 14)
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55th Congress, | SENATE. ( Document

Sd Session. J (No. 172.







IN 1898


(ten maps in accompanying envelope)

Prkpabkd in accordance with Pubuc Resolution No. 25 of the Fifty-fifth Congress
Third Session, approved March 1, 1899








Summary of Plans and Results, by The Director 11

Part I. — Special Reports of Expeditions.

Report of the Sushitna expedition, by Gr. H. Eldridge and Robert

Muldrow 15

General topographic features of the route 15

Geology 19

rormations 19

Granite 19

Sushitna slate series 20

Cantwell conglomerate 20

Kenai series 20

Recent deposits 21

Eruptives 21

Structure 21

Mineral resources 23

Gold 22

Coal '. 22

Possibilities of agriculture 24

Clinaate 24

Temperature and weather observations in 1898 25

Weather conditions in 1897 25

Routes to the interior 26

Magnetic variations, Sushitna River, 1898 27

Report of the Kuskokwim exjoedition, by J. E. Spurr and W. S. Post. . 28

Itinerary 28

Topography 29

Cook Inlet. 29

Skwentna region 30

Kuskokwim region 30

Kanektok region 31

Togiak region 31

Nushagak region 31

Naknek region 31

Population 31

Climate 32

Vegetation and birds 33

Game and fish 34

Geology 34

R6sum6 36

Mineral resources 36

Land and water routes 37




Tablf of (listjincos iiloii}; route from Tyoiiek to Kutinai 38

Mn;;ii(>tic variations, soutliwcstcrn Alaska. IHllH 39

Report on tlu" rcjfion Itctwccn Hesurrcction Hay and the Tanana

Kiver. l>y W. ( '. Mendenliall 40

Int rod net ion 40

(itH);rniphy and topojcraphy 41

('(K)k Inlet and I'rince William JSound 41

(leneral toi)o;j:ra|)hy 41

Routes 43

Met liods of t ravel 44

Ueneral j^eolo^fv 45

Sunrise series 45

Atre 45

Matanuska series 46

Age 46

Greenstone series 46

Tanana series 46

Known {jold districts 47

Tnrnajj:ain Arm 47

Matanuska Valley 47

(General gravel sheet 47

Coal \ 48

Timber and j^rass 48

Game 49

Climate 49

Aprrieulture 50

Inhabitants 50

Report on Prinee William Sound and the Copper River refjion, by

F. C. Schrader 51

Itinerary 51

Geography '. 53

Pojiulation 52

I'rince William Sound natives 52

Prince William Sound whites 52

( 'opper River natives 52

Prospectors and explorers 53

Climate 53

Prince William Sound 53

Valdez sununit 54

Copper River district 54

Animal life 54

Kish 54

(Quadrupeds 54

Birds 54

I nsects 55

Vegetation 55

Prince William Sound 55

Copper River district 55

Topography 55

Geology 57

Orca series 57

Valdez series 57

Age of the Valdez and Orca series 57



Copper Mouiituiu greenstone or aniphibolite-sehist 57

Klutena series 58

Igneous rocks 58

Copper River silts 58

Mineral resources 59

Copper 59

Copjjer Mountain mine 59

(jrladhaugh Bay mine 59

Latouclie and Knights islands 59

Gold-bearing quartz 60

Placers 60

Coal 61

Routes and trails 61

Table of approximate distances by Gr lacier trail 63

Report of the White River-Tanana expedition, by W. J. Peters and

Alfred H. Brooks 64

Narrative 64

Previous explorations 65

Geography 65

Geology 67

Nasina series 67

Basal gneissoid series 68

Tanana schists '. . 68

Wellesley formation 68

Nilkoka formation 68

Younger sedimentary rocks 68

Igneous rocks 69

Summary of the bed rock geology 69

Glacial phenomena ; . . . 69

Silts and gravels 69

Volcanic ash 69

Mineral resources 70

Gold 70

Copper 71

Coal : 71

Timber 71

Game 71

Climate 72

Agriculture 73

Routes and means of transportation 73

White River 72

Trails to White River 73

Tanana River 73

Trails to the Tanana 73

Railway routes 74

Inhabitants 74

Whites 74

Indians 74

Marks and monuments along the route of travel 74

Table of approximate distances 75

Magnetic declinations 75

Report of the Fortymile expedition, by E. C. Barnard 76

Itinerary 76



Metlnxls ssit-r. ^'ildridfce' and Spnrr, ffcolo^ists, respectively.
After paitinj; froln tire Barnard and Peters parties at tSkagway,
Messi-s. Hldridp:e and Spnrr with their Jissociates continned in the
WhecVnifi to Cook Inlet, from which point they were to proceed up
the Snshitna to abont latitnde iV.\° 40', where several forks of the river
combine. At tliis point the Kldridge parly, with ^Ir. INIuldrow as
topt>j;ra])hcr, was to commence the exploration of the northeast por-
tion of the Snshitna drainage basin, and, if possible, to close on Mr.
Peters's snrvey down the Tanaua. The other part}', under Mr. Spurr,
with ]\rr. I'ost as topographer, was to proceed westward across the
divide between the Sushitna and the Kuskokvvim for the purpose of
surveying the head waters of the Kuskokwim and of determining the
uavigabilitj' of that stream by descending to the usual portage to the
Lower Yukon.

All the parties expected to rende/vons at St. Michael l)y September
15, but the contingencies of exploration in remote regions could not
be accurately foreseen and the chiefs of parties were at liberty to pur-
sue such homeward routes as might seem most favorable under the
conditions existing in the autumn. The Barnard and Peters parties
descended the Yukon and returned from St. Michael; the Eldridge
party was forced to return to Cook Inlet and thence to Seattle; and
the Spurr party, on arriving at the mouth of the Kuskokwim, found
opportunity for more extended exploration, and returned along the
coast to Katmai, where it was picked up by the Alaska Commercial
Company's steamer Dora.

The energj' with which these parties pursued the explorations and
surveys assigned them has been characteristic of American explorers,
but is none the less creditable to these men. The methods with
which they determined the positions and topography of their routes
of travel, and the accuracy with which they observed the geologic
and natnral-history featnres of the country traversed, combine to
render the results far more valuable than has usually been the case
under similar circumstances. The reports which follow set forth
brietiy the principal results of their observations, giving in untechnical
language useful information with reference to the geography, geology,
mineral resources, animals, vegetation, climate, and population of the
districts explored. All statements have been condensed.

To supplement the original information comprised in these several
reports a compilation of all available authentic data has been made
and is included in the second part of this publication. This second
part relates to the whole of Alaska, which is divided into geographic


proviuces, and each proviuce is described separately. Finally, a series
of condensed tables of important information has been added.

The work of 1898 increased much the definite knowledge of
Alaska which had been obtained by explorations scattered over the
preceding years. The map of that portion of Alaska lying south
of the Yukon has been almost completely reconstructed. Rivers pre-
viously known have been for the first time accurately surveyed, and
many new lakes and rivers have been discovered. The movmtain
systems have been traced out, and magnificent ranges 12,000 to
20,000 feet in altitude have been found where previously the maps
presented blanks. The source of the Kuskokwim has been found
far distant from where it was supposed to be, in high mountains,
where a swampy plain had previously been believed to exist. The
phj'siography of southern Alaska has been independently studied and
worked out by each party, and there is substantial agreement in all
the principal incidents of interpretation. The important question of
general glaciation has received special attention. The geologic for-
mations and the distribution of coal-bearing and known gold-bearing-
rocks are broadly determined. Much valuable information has been
accuinulated in regard to the distribution of timber and game, with
possibilities of agriculture or of stock raising, and in regard to feasible
routes for pack trails, wagon roads, or railways, by which the country
may be traversed or the interior reached.

The present report has been prepared in accordance with the special
act of Congress, to accompany the maps of the several routes of explor-
ation and the revised general map of Alaska. It has been written by
the several geologists and topographers of the expeditions, and the
whole has been edited by Mr. Spurr. Fuller discussion of the geology
and physical geography of the regions visited by the different parties,
with details of scientific and economic interest, will be presented in
the Twentieth Annual Report of the Survey.


By G. H. Eldridgk and Robert Muldrow.


Cook Inlet is a structural basin of vast size, open to the North
Pacific at its southern end. At present the sea occupies about half
the total area, the remaining portion having been gradually filled
and elevated until it now forms a broad valley 75 to 100 miles wide
by 150 to 175 miles long. The inclosing mountain ranges have an
intricate and rugged topography and an approximate average height
of 8,000 to 10,000 feet, but they are sharply saw-toothed and relieved
by numerous peaks 12,000 to 20,000 feet in altitude. The loftiest
and most rugged mountains are those constituting the Sushitna-Tanana
divide; they include the highest peak on the North American conti-
nent — Mount McKiuley, 20,464 feet in elevation — and may be called
the Alaskan Mountains. West of Mount McKinley, in the same
range, are two peaks closely approximating 16,000 feet. The ranges
which lie west of Cook Inlet and the Sushitna Valley resemble the
Alaskan Mountains in ruggedness, and include a number of lofty
peaks, of which the volcanoes Redoubt and Iliamna, 11,000 and 12,068
feet high respectively, are the most interesting. East of the Sushitna
Valley and Cook Inlet, also, the mountain ranges have great rugged-
ness, and there are many points but little lower than those in the
Alaskan Mountains. To the range north of the Kenai Peninsula the
name Talkeetna may be applied. In all these ranges the crest line is
saw-toothed, while the slopes are cut by gorges 4,000 to 10,000 feet
deep, with precipitous walls, and their upper courses glacier- filled.
At the head of Cook Inlet and west of the mouth of the Sushitna
River lies Mount Sushitna. This peak is 4,280 feet high, forming the
southern extremity of a low ridge that is cut by the Yeutna, the chief
western tributary of the Sushitna, a short distance above its mouth.

The vast watershed inclosed by all these mountains is drained by
the Sushitna river system. What is locally regarded as the main
branch of this stream rises far in the interior, in the comparatively
low country between the mountains of the St. Elias and Alaskan sys-
tems, and has a course very irregular but in the main southwest.
About SO miles from the inlet it receives the Chulitna, and from this
point the river has an almost due south course. The Chulitna has

' See map No. 2, in accompanying envelope.
2-Alaska. 15


iiiaiiN forks risiuf; in the Alaskan Mountains, some of them originating
in the canyons of Mounl iMcKinley itself. Both the main river and
the dnililna carry heavy volumes of water, each stream averaging
perhaps one-fourth mile in widlh. A mile below the Chulitna the
Sushitna receives from the northeast the Talkeetna, a tributary of
secondary size rising in the Talkeetna Mountains, and '20 miles above
the mouth of the Sushitna the Yentna enters from the northwest. The
last-named stream rises in the mountains forming the divide between
the Sushitna and the Kuskokwim, and is approximately 150 miles
long. Data relating to the region drained by the Yentna may be
found in the accompanying report by Messrs. Spurr and Post (p. 28)
All three of the great tributaries of the Sushitna carry vast amounts
of sediment, derived from glaciers and from the banks, which are con-
stantly wearing away. Their currents are between 4 and 5 miles an
hour, and their main channels are deep.

The valley of the main Sushitna below its continence with the Chu-
litna merges with that of the Yentna and forms a gently undulating
tract of country, 100 to 125 miles broad, which rises gradually from
4 or 5 feet above high tide at the mouth of the river to 300 to 400 feet
at the border of the foothills. From the summit of Mount Sushitna
the vallej' appears to be well timbered with poplar, spruce, and birch,
the latter on ridges and other elevated portions. Meadow and swamp
land is freely interspersed with the timbered areas, and lakes form a
conspicuous feature. At the periphery of the valley the country is
generally high and rolling, in some localities forming foothills to the
adjacent ranges, while here and there the general valley itself is cut
by low yet conspicuous ridges, some of igneous rock, some of specially
heavy gravel deposits, and, rarely, some of sedimentary rocks.

At the mouth of the Sushitna is a large delta that is traversed by
three or four channels of considerable size, of which the westernmost is
used by Indians and traders for access to the river, since it is deeper
and shorter and safer of approach than are the others. The delta
above the general tide level is a vast body of marsh land, relieved
along the channels by fringes of alder and poplar and in the upper
portion by spruce. As the distance up the river increases, the tim-
ber, especially spruce, grows thicker. Between the delta and the
mouth of the Chulitna the Sushitna maintains a width of one-half to
2 miles, and is for the greater portion of the distance studded with
islands, though there are occasional stretches where the stream flows
through a single broad and deep channel. The stage of the water
causes marked variation in the relative proportion of islands and bars,
thus seriously affecting the ease with which the river is ascended,
since, on account of the current, the greater portion of the distance has
to be made by towing, either in the stream or along the main shores.
Minor channels, however, frequently enable one to avoid the swifter


currents. The main channel is generally well defined and of consid-
erable depth, sufficient, it is believed, for the passage at all times of
light-draft stern- wheel steamers. The banks of the river in the delta
region are of sand, and rise but 5 or 6 feet above ordinary water level.
With an occasional exception it is not until a point a mile or two
above the Yentna is reached that the gravel banks, so common along
the river above, become a pronounced feature. From this point, how-
ever, these banks continue quite to the foothills, varying in height
from 25 to 200 feet. There are usually no bottom lands, in the sense
in which the term is accepted in the United States, along either the
main river or its tributaries.

From 5 to 10 miles above the mouth of the Chulitna the character
of the main Sushitna Valley changes; it now lies in the foothills, and
a little farther up is inclosed between ridges 3,000 to 4,000 feet high,
which separate it on the southeast from the Talkeetna and on the
northwest from the Chulitna. The stream itself runs in a picturesque
gorge 400 to 500 feet deep, which has been cut in the bottom of an
earlier valley. Forty-five miles above the mouth of the Chulitna,
falls and rapids are reported in the main river, which prevent boating
both upstream and downstream. However, for a distance of about
25 miles a portage may be made over the highlands on the northwest
side of the river, and boats may then be again utilized for transporta-
tion of supplies nearly to the great glaciers at the head of the stream.
The current in the upper river is much swifter than in the lower.

The ancient valley of the Sushitna, referred to above, is nearly
closed at its lower end, 10 miles above the Chulitna; it broadens to 6
or 8 miles in the vicinity of Indian Creek, 25 miles farther up, and
maintains this width in a general way as far as the great bend in the
river 50 miles above the Chulitna. Beyond this it is said to further
broaden and to take the character of an open highland country, with
mountains here and there about its periphery. Although this early
valley of the Sushitna shows evidence of having once been well worn
down, nearly to base-level, it has since been deeply cut by mountain
torrents and its floor has been rendered uneven by erosion of the
underlying highly folded slates, so that the region is one of hills and
dales beautified by growths of spruce and birch and interspersed with
open grassy or moss-covered parks and lakes of great picturesqueness.
The timber line in these mountain valleys reaches as high as 3,000
feet above sea level; above this the alder growth extends for 500 or
600 feet, and is succeeded finally by moss-covered slopes or bare rocks.

The general valley of the Chulitna was observed from the range
separating it from the Sushitna Elver at a point opposite the mouth
of Indian Creek, the distance between the streams here being about
^5 miles. The course of the main Chulitna is a little west of south.
It receives numerous large tributaries, glacial and otherwise, from the


iiKumtaiiis to tlif wi'st. while I'nmi the east there enter two impor-
tant hniiiclu's, led by t

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Online LibraryGeological Survey (U.S.)Maps and descriptions of routes of exploration in Alaska in 1898 : with general information concerning the territory → online text (page 1 of 14)