DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

CHARLES IX WALCOTT, DIRECTOR

THE

RAMPART GOLD PLACER REGION

ALASKA

L. M. PRINDLE-AND FRANK L. HESS

WASHINGTON

GOVEKNMENT PRINTING OFFICE

1906

COMENTS.

Page.

GEOGRAPHY AND GEOLOGY, BY L. M. PKINDLE ................................ 5

General statement. I.................................................. 5

Geography. ..............................:...................... ..... 8

General description............................................... 8

Relief ........................................................... 9

Drainage .................^...................................... 12

Vegetation....................................................... 16

Geology ............................................................. 16

General features.................................................. 16

Stratigraphic succession........................................... 17

Sedimentary and metamorphosed formations....................... 18

Pre-Devonian. :.............................................. 18

Devonian..................................................... 18

Carboniferous................................................ 21

Cretaceous.............................. v ................... 22

Tertiary ............:....................'................... 22

Quaternary ...........i....................................... 23

Igneous rocks..........:......................................... 23

Granitic rocks................................................ 23

Monzonitic rocks............................................. 24

Greenstones .................................................. 24

Basalt....................................................... 24

Summary......................................................... 24

THE GOLD PLACERS, BY F. L. HESS ........................................ 26

General statement.................................................... 26

Minook Creek group .................................................. 27

Minook Creek.................................................... 28

High bench........................................................ 30

Creeks cutting the high bench..................................... 31

Hunter...................................................... 32

Little Minook................'................................. 33

Little Minook Junior......................................... 35

Hoosier......................i............................... 36

Florida......................................-.-.-......:.... 36

Origin of the gold ............................................ 37

Other tributaries of Minook Creek................................. 37

Euby......---.-.............-.......:..'..................... 37

Slate-.....-.-.------------.....--..--.-.------------.--.-.-- 38

Baker Creek group ................................................... 38

General description .............................................. 38

3
r

4 CONTENTS AND ILLUSTRATJONS.

THE GOLD PLACERS Continued. Page. 

Baker Creek group Continued.

The creeks and benches........................................... 40

Eureka Creek ............... ~................................... 40

Pioneer Creek................................................ 40

What Cheer Bar ......................................... 41

Seattle Bar................................................ 42

Doric Creek............................................... 42

Other bench gravels...................................... 42

Shirley Bar................................................... 42

Glenn Creek.................................................. 43

Gold Run.................................................... 43

Rhode Island Creek ......... . _............................... 44

Seattle Creek .... ..7 .......................... 1.......... 1.... 44

Bench west of Rhode Island Creek............................ 44

Omega Creek............'..................................... 44

Chicago Creek................................................. 45

' Thanksgiving Creek .......................................... 45

Hutlina Creek................................................ 46

Water for hydraulicking.......................................... 46

General conclusions .... L .......................................... 47

Troublesome Creek group............................................. 47

General description .............................................. 47

Creeks prospected................................................ 47

Quail Creek ....................................J\............ 47

Gunnison Creek.............................................. 48

General summary ..................................................... 48

INDEX ...................................~............................... 51

ILLUSTRATIONS.

PLATE I. Geologic sketch map...I....................................... 5

II. A, View northeastward along the ridges of the White Mountains;

 B, View southeastward toward head of Golden Creek........ 10

III. Rampart placer region, showing distribution of auriferous gravels. 26

IV. A, View westward from Idaho Bar, down Little Minook Creek, 

showing portion of high bench and intermediate bench; B, 

Gravel of high bench of Minook Creek exposed in tunnel on 

Idaho Bar................................................... 30

V. A, Automatic dump gate discharging, Claim No. 3 below, Little 

Minook Creek; B, Hydraulicking on Hunter Creek, about 4 

miles above the mouth..................................... 32

VI. Gold specimens .............................................. 38

VII. A, Valley of Glenn Creek, looking north, showing sluices, etc.; 

B, View westward up Quail Creek from the east side of Troublesome Creek................................................ 42

FIG. 1. Diagrammatic sketch of Minook Valley........................ 29
U. S. GEO LOGICAL SURVEY BULLETIN NO. 280 PL.I

GEOLOGIC SKETCH MAP

OF THK

RAMPART REGION, 

ALASKA.

and F. L.Hess, 1904-.

VERTICAL SCALE OF SECTIONS IS FOURTIMES HORIZONTAL

LEGEND 

QUATERNARY

ALluvixrai

TERTIARY

(Kenai formation)

CRETACEOUS?

Impure sandstone

CARBONIFEROUS

Pennsvlvaiuan ?

D EVON IAN

limestones, {greenstones,

qnarlzitus.reol andblack

slates

Cherts, slates, 

and greenstones

PRE-DEVONIAN r i

,

jquartz^ini ca schists,

Sarapliferoiis schists,

arid crystnlliip limestone

Tntnisjvp granitic and. 

monzonilic rocks
THE RAMPART GOLD PLACER REGION, ALASKA."

By L. M. P.RINDLE and F. L. HESS.

GEOGRAPHY AND GEOLOGY

By L. M. PRINDLE.

GENERAL STATEMENT.

The Rain part region is in the central part of Alaska, near the intersection of the 

one hundred and fiftieth meridian and the sixty-fifth parallel. It is.in the western 

part of the large area embracing approximately 40,000 square miles delimited by 

Yukon and Tanana rivers and by the international boundary, 300 miles to the east, and 

is located where the distance in a north and south direction between the two rivers 

is hardly 50 miles (PI. I). . .

The Rampart region is one of the four most important gold-producing regions in 

this interstream area. The Fortyinile, near the boundary, the Birch Creek, and the 

Rampart regions are adjacent to the Yukon at intervals of about 140 miles westward 

from the boundary. The Fairbanks region, the most recently developed and at the 

present time the most productive, is in Tanana Valley about 12 miles north of the 

river and about 260 miles from its mouth. The Rampart region is about 80 miles 

northwest of the Fairbanks region, and all the creeks of present economic importance are within 30 miles of the Yukon and belong to the drainage systems of both 

Yukon and Tanana rivers.

The region has passed through many stages characteristic of the life of a placer 

camp. Some of the creeks were prospected as early as 1893 and became active producers by 1896, when the region became of equal prominence with the Fortyinile 

and Birch Creek regions. Many were attracted by the favorable results, and during 

the winter of 1898-99 the town of Rampart, the supply point for the camp, contained 

about 1,500 people. After the preliminary stage of prospecting and the subsequent 

excitement of the boom days, with their excess of hopes and population, the camp 

settled down to the laborious existence of an average producer, influenced from time 

to time by the discoveries of gold in other portions of Alaska and rewarded occasionally by discoveries in its own territory. During the last two years discoveries 

have been made which have contributed to the permanence of the camp and illustrated the possibilities still existing in a region which has already been under investigation for several years. The recent introduction of hydraulic methods, too, 

entailing the expenditure of considerable capital, has given further importance to 

the locality, which during 1904 had a population of about 300 and a production of 

approximately $235,000.

«An abstract of this paper was published iu Bull. U. S. Geol. Survey No. 259, pp. 104-119.

5
6 GEOGRAPHY AND GEOLOGT OF RAMPART REGION.

The towns of Eagle, Circle, and Kampart, on Yukon River, and Fairbanks, on 

Tanana River, have developed as supply points for the mining regions in their 

vicinity. The town of Rampart, with a population of about 200, is on the south 

bank of the Yukon, 170 miles below Circle and about 70 miles above the junction 

with the Tanana, at a point where the Yukon, after pursuing for a few miles a 

southerly course, bends squarely to the west and sweeps in a deep channel past the 

hills which bound the south side of the rather open valley. A narrow-terraced 

slope between these hills and the river is picturesquely occupied along the water 

front and hillside in the background by the irregular collection of buildings which 

forms the town. There is an air of importance about the place, and it possesses, 

also, a kind of dignity which the pervasive majesty of the great river and the vast 

loneliness of the country through which it flows have conferred upon every one of 

these small isolated outposts of civilization.

« Supplies are received from the outside world by way of either St. Michael or Dawson. By the first course they are shipped by water to St. Michael and carried thence 

by river steamers up the Yukon, a distance of about 900 miles, to Rampart. By the 

second course they are shipped from Skagway by the White Pass and Yukon railroad through Canadian territory to White Horse, by river steamer to Dawson, and 

by the lower river boats, a distance of 500 miles farther, to Rampart. The fact 

that in the spring navigation opens first oh the upper Yukon has led to a preference 

of the Dawson route when it is desired to have supplies arrive at their destination 

early in the season. The first-class passenger rate during the summer of 1904 from 

Seattle to Rampart by way of St. Michael was $127.50; that by way of Dawson was 

$111. The freight rates have a wide range of variation, according to the kind of 

material and the time of year. The approximate rates on ordinary supplies by way 

of St. Michael and Dawson respectively during 1904 were $57 and $106 a ton.

The gold-producing creeks are at distances of 5 to 30 miles from Rampart, and are 

connected with the town by trails. Minook Creek enters the Yukon from the south 

about a half mile above Rampart. The main trail follows its valley a distance of 

about 20 miles to the head, and then passes over the divide at an elevation of about 

2,000 feet, and extends to the creeks in the southern part of the region. Side. 

trails leave the main trail at intervals for the various creeks. Supplies are transported over these trails by pack train in the summer and by dog or horse sleds in the 

winter, i The summer rates are 4 to 15 cents a pound, according to distance, and the 

winter rates to the same localities are 2 to 6 cents a pound. Summer traveling is bad. 

The trodden muck along the valley sides and bottoms favors the accumulation of 

water, and the interlacing ditch-like trails entail much hardship upon the pack animals, which flounder along them, and increase the cost of gold production to the 

miners, none of whom are in a position to improve them. Most of the freighting is 

consequently done in the winter time. Several outfits at Rampart are in the freighting business, and in both summer and winter make trips at regular intervals to the. 

creeks.

There is a station of the Government telegraph line at Rampart which affords communication by way of the Tanana with other portions of Alaska and the outside at 

rates which are low in comparison with the advantages which may thus be secured. 

The mail facilities are improving from year to year and, as the rates on small quantities of light material compare very favorably with the freight rates, this method of 

obtaining such supplies from the States during the summer season is often utilized 

and is of considerable benefit to the people.

The four important gold-producing regions of the Yukon-Tanana country have 

been visited at various times by parties from the Geological Survey, which have 

been engaged either in mapping these regions and the little-known areas between 

them, or in studying the gold-bearing deposits and the distribution of the formations 

which occur in the gold-producing regions. The results have been embodied in
GENERAL STATEMENT. 7

maps and reports, some of which have already been published by the Survey, while 

others are in preparation.

The Fortyniile, Birch Creek, and Rampart regions were visited by a survey party 

consisting of Spurr, Goodrich, and Schrader in 1896, and the results are to be found 

in the report of that expedition.«

In 1902 Collier, in the course of an investigation of the coal resources along the 

Yukon, studied the gold placers in the southern portion of the region. & Late in the 

fall of the same year Brooks, near the close of his reconnaissance about Mount 

McKinley, traversed a portion of the Rampart region. c

The work of all these expeditions has resulted in an accumulation of material, 

partly topographic and partly geologic, which becomes increasingly valuable to the 

people of the region in tracing the occurrence and distribution of the gold-bearing 

deposits.

' During the season of 1904 the writer, under instructions from Mr. Alfred H. 

Brooks, geologist in charge, assisted by Frank L. Hess, with a packer, cook, and 7 

horses, made a geologic reconnaissance overland from Eagle by way of Fairbanks to 

Rampart, and it was in the course of this trip that' the observations were made and 

the material was collected which form the basis of this description.

After concluding work in the Fairbanks region the party started overland from 

.Cleary Creek for Rampart on the 5th of August, and on the 26th reached a tributary of 

Troublesome Creek, in the Rampart region, at a point where the Brooks party had 

camped two years before. There in 1904 the smoke of a camp fire indicated a /one 

of prospecting. The remainder of August and the first part of September were 

spent among the gold placers. On the 20th of September the party started by 

steamer up the Yukon, and reached Seattle on the 5th of October, only fifteen days 

from the time of leaving Rampart.

The route chosen by the party lay northwest from Cleary Creek across the White 

Mountains and the ridges beyond to the southern limit of Yukon Flats, thence 

southwest to the main divide between the Yukon and Tanana drainage systems, 

thence Avest along this divide to the rough hills which mark so conspicuously the 

location of the Rampart region.

The conditions of travel by pack train in the Yukon-Tanana country are comparable with those prevailing in portions of the States and deserve no special mention. 

The horses are all used as pack animals and carry generally not more than 175 

pounds. The divides are preferred for travel, as they are mostly free from timber 

and generally afford a firmer footing than the valleys. Some of the lower divides, 

however, are thickly covered with small spruce, and in a large area east of the Rampart region the moss and grass of the divides form a niggerheaded surface which 

retards the progress of the pack train. The streams within the hill country occasionally offer better conditions for travel than the divides. They can be crossed-and 

recrossed at will and their gravel-covered bars can be followed sometimes for miles. 

At times of high water, however, they may impede travel. Grass grows luxuriantly 

in some of the sunward-facing draws and in portions of the larger valleys, and is 

generally in good condition from the latter part of June to at least the first of September. Although the horses sometimes have difficulty in obtaining sufficient food, 

and are sometimes so tormented by mosquitoes as to be unable to eat quietly where 

there is abundance, they generally end the season in fairly good condition.

The members of the party always received active help from all those among 

whom their labors were performed,- and pleasantly remember many kindly acts of

« Spurr, ,T. E., Geology of the Yukon gold district, Alaska: Eighteenth Arm. Kept. U. S. Geol. Survey pt. 3, 1898, pp. 87-392.

b Collier, A. J., The Gleun Creek gold-mining district, Alaska: Bull. U. S. Geol. Survey No. 213, 

1903, pp. 49-5G. Coal resources of the Yukon, Alaska: Bull.TJ. S. Geol. Survey No. 218,1903, pp. 41-43, 

. c Brooks, A. H., Exploration in the Mount McKinley region, Alaska: Prof. Paper U. S. Geol. Survey 

No. . (In preparation.)
8 GEOGRAPHY AND GEOLOGY OF RAMPART REGION.

hospitality. Alaska is a land of strong contrasts, and when, in the gloom of a rainy 

night, amid the dripping brush and running waters of a sodden valley, the cheerful 

light of a miner's cabin draws the traveler to unaccustomed warmth and dryness, 

the heartiness of the welcome illustrates most forcibly the hospitable spirit of the 

people in the midst of the ofttirnes stern inclemency of the outer world.

This bulletin is intended to supplement the results of recent work in the Fortymile, Birch Creek, and Fairbanks regions" by a similar description of present conditions in the Rampart region and to include also a general description of' the areas to 

the east, where the rocks of the Rampart region have their eastward extension. The 

writer has had the able assistance of Mr. Hess throughout the field and office work, 

and the results of the efforts of both in the field have been divided in the office for 

the sake of greater economy of time in the preparation of this report. Mr. Hess has 

described the gold placers, while the account of the general economic conditions, the 

geography and geology, and the supervision of the whole, have devolved upon 

the writer. His statement of the geology, which is merely preliminary, will be 

more fully developed in a description of the geology of the entire Yukon-Tanana 

country which is in preparation.

GEOGRAPHY.

GENERAL, DESCRtPTIOlSr.

There is a large area north and west of the Fairbanks region which is limited on 

the north and south by the converging courses of Yukon and Tanana rivers, respectively, and is terminated on the west by their confluence. It is shown upon the 

accompanying geologic map (PI. I), which indicates the main drainage lines and 

the route of the party from Chatanika River northward to the southern limit of 

Yukon Flats and thence southwest to the creeks of the Rampart region. This map, 

while only approximately correct, in so far as it is based upon the work of the party 

in which distances were estimated by pacing, directions by pocket compass, and 

altitudes by aneroid barometer, represents with fair accuracy the general relations 

of the narrow belt of country traversed to the larger area of which it forms a part.

The surface of this area presents the same kind of features as those to the east, but 

there is considerable difference in their development, due partly to the narrowing 

space between the two rivers and partly to difference in the bed rock. There is the 

ridge and valley feature which occupies the greater part of -the area and the flanking 

lowlands, on the north the Yukon Flats, and on the south the flat area drained by 

tributaries of the Tanana.

The ridges show a general uniformity in height of 2,000 to 2,500 feet, but some 

rise conspicuously above their surroundings to an altitude of nearly 5,000 feet and 

others become broader and lower and merge into the valleys on each side.

The divide between the drainage systems of Yukon and Tanana rivers throughout 

the Yukon-Tanana country has an extremely irregular course, due to the extensive 

ramifications of many streams among ridges of nearly equal height, and in this 

western part of the country in addition to the irregularity of direction there is a 

great variation in altitude. It is in places a prominent sharply defined ridge, while 

in other localities it becomes a low flat, separating with broad indefiniteness the 

Avaters which linger on its surface.

The features of greatest prominence are the White Mountains, extending northeast and southwest through the eastern part of the area, and the high group of hills 

50 miles west of the White Mountains, in the vicinity of Rampart. The country 

between these two main features comprises many ridges, which toward the north 

are in general higher arid break off with abruptness to Yukon Flats. The southern

"Prindle, L. M.,Gold placers of the Fortymile, Birch Creek, and Fairbanks regions, Alaska: Bull. 

U. S. Geol. Survey No. 251,1Q05.
GEOGRAPHY BELIEF. ' 9

limit of the hill country is less abrupt and the ridges merge gradually into the lowlands of the Tolovana. . '

The valleys, too, exhibit as much variation as the ridges. There are deep, steepwalled canyons which lead away their waters quickly, and there are open spaces 

where the waterways are only slight depressions in a rolling surface having an almost 

imperceptible grade. The streams throughout this country often pursue most irregular courses before they finally extricate themselves from the many ridges and become 

identified with their respective drainage systems. The important tributaries of the 

Yukon are Beaver Creek, Hess Creek, and Minook Creek; those tributary to the 

Tanana are Tolovana River and Baker Creek.

The hill country gives place along an east-and-w'est line which crosses the Yukon 

a short distance above Fort Hamlin to one of the most striking features iii the interior 

of Alaska Yukon Flats. From the base of the overlooking ridges, 1,500 to 2,000 

feet above them, they extend northward toward the plateau country fronting the 

Rocky Mountains and eastward far out beyond the sky line. The sparsely timbered 

surface is somewhat uneven and broken where minor ridges run out into it from the 

base of the hills. It is dotted with a feAV small lakes, and the minor streams which 

furrow deeply the northern slopes of the hills run irregularly across it in no Avelldefined valleys of their own. Through it all can be seen long lines and crescentshaped areas of water where the many interlacing channels of the Yukon spread 

widely over the great surface. The lowlands along the southern border of the hill 

country, the Tolovana and Baker flats, although occupying large areas, ,are local 

features- less sharply differentiated from the hills and more closely related to their 

respective drainage systems.

RELIEF.

The distance in a straight line from a point on Chatanika River about opposite the 

mouth of Cleary Creek to Yukon Flats is about 60 miles, and the section may be 

roughly divided into three parts the country from Chatanika River to Beaver 

Creek, the White Mountains in the space between the two parts of Beaver Creek, 

and the ridge country between the northern part of Beaver Creek and Yukon Flats.

A space 20 miles wide between Chatanika River and Beaver Creek is occupied 

by the broad ridge which separates the tributaries of the two streams. This ridge 

extends in a northeast and southwest direction and has an .elevation of about 1,000 

feet above the valleys on each side. It is very unsymmetrical. The southeast slope 

is rather steep and is worn by short tributaries of the Chatanika into minor lateral 

spurs, which descend abruptly to the valley.. The northwest slope presents a striking and unexpected contrast. Long, broad, lateral ridges extend their dark, spruceclad, undulating surfaces with gradually diminished height toward the steep-sided 

serrate ridges of the White Mountains and finally 15 miles away merge into the open 

valley of Beaver Creek. These ridges, so uniform in height and even in outline, are 

separated by wide, shallow, sparsely timbered valleys of equal uniformity, occupied 

by small, weak streams which flow with gentle gradients for several miles to Beaver 

Creek. .

The AVhite Mountains (PI. II, A, p. 10), as seen from the highest parts of this 

ridge, rise abruptly from the somber foreground which extends with apparent continuity to their base, and not till the explorer reaches the edge of Beaver Valley does 

he understand their true relation to it and to the country to the south. They extend 

in a northeast and southwest direction a distance of 50 or 60 miles and form perhaps 

the most persistent group of ridges in the Yukon-Tanana country. They rise 2,000 

feet or more above the base and increase in height toward the northeast, where some 

of the highest points have an altitude of about 5,300 feet. To the southwest they 

narrow rapidly to a single, knife-edge ridge, which terminates at Beaver Creek about 

35 miles nearly north from Fairbanks. The uneven ridges exhibit a great variety of
10 . GEOGRAPHY AND GEOLOGY OF RAMPART REGION.

topographic detail. The edges of upturned limestone beds have been reduced by 

weathering to more or less disconnected, precipitous, shattered masses which rise in 

places to heights of several hundred feet above the general outline and impart to the 

range a peculiarity of form almost as striking as that of color. The rocky slopes are 

made less precipitous by the piles of debris into which they plunge, and these in 

turn run out into a gradually sloping more or less extensive base covered with the 

vegetation of the tundra and flattening until it merges with slight abruptness into 

the valley of Beaver Creek. The rocky slopes above are furrowed with steep rockstrewn gulches which are mostly dry. In the lower part these gulches become narrow valleys inconspicuously sunk in the surface and carrying ordinarily but little 

water.

Southwest of the White Mountains, across Beaver Valley, bare even-topped ridges, 

nearly uniform in height, form the background of the amphitheatral area around 

the bend of Beaver Creek and extend northward to become laterally adjacent on the 

west to the terminating ridge of the White Mountains. A few jagged points project 

inconspicuously from the level of these ridges and seem to indicate the continuation 

in this direction of the formations so accentuated to the northeast and to emphasize 

the loss of topographic individuality that has been sustained. A few miles west of 

the southern part of the mountains the country opens widely toward the southwest, 

where a broad low divide, with an altitude of approximately 1,500 feet, separates 

the Beaver waters from streams tributary to the Tanana.

Northwest of the White Mountains, between Beaver Creek and Yukon Flats, 

in a distance of about 20 miles, there are several nearly parallel ridges, the, trend of 

which is at first northeast parallel with the White Mountains, but changes gradually 

as they are crossed from one to the other northward until the trend of the ridges 

near the Flats is approximately east and west. The ridges are of various heights, 

with an average of perhaps 2,500 feet, and have a somewhat uneven outline. Between 

the steep-sided prominent ridge which forms the northern limit of Beaver Valley and the equally prominent ridge which overlooks the Flats there is the divide 

which separates the headwaters and tributaries of three important streams Beaver 

Creek, Hess Creek, and Tolovana Kiver. This divide, in comparison with the ridges 

which start from it and gain in prominence down their respective drainage systems, 

is low and inconspicuous and shows an area of open country where.long, bare, gradual 

slopes present the clean-cut appearance of meadows freshly mown (PI. II, B). The 

drainage is marked by lines of green traced along the flatly intersecting bases of the 

slopes, vivid in color toward the sources of the streams where only willow patches 

grow and of a more somber shade lower down the valleys where scattering groups 

and lines 'of spruce are delicately outlined against the brownish background.

Northward the country rises gradually to the level of an even-topped east-west 

ridge 2,000 feet in height, surmounted by a few steep-sided domes of greater height, 

and then descends by intermediate flanking ridges with more or less abruptness to 

the Flats. The northern and southern slopes of this ridge are deeply cut by minor 

tributaries and toward the west it terminates finally as a spur between Hess Creek 

and one of its northern tributaries. The flanking ridges on the north replace it and, 

with approximately the same altitude,,continue westward toward the Yukon at Fort 

Hamlin.

The main divide, between the Yukon and Tanana drainage systems is about 25 

miles south of the Yukon and extends in a nearly westerly direction toward the hills 

of Kampart. There.are no topographic features of special interest. The divide is in 

places a well-defined ridge sharply differentiated from its surroundings; at other 

localities it is less conspicuous than the numerous long lateral spurs which descend 

irregularly from it toward the valleys of Hess Creek and Tolovana River, and at one 

locality, as far as could be observed, the headwater streams from the north and south
U. S. GEOLOGICAL SURVEY BULLETIN NO. 280 PL. I

A. VIEW NORTHEASTWARD ALONG THE RIDGES OF THE WHITE MOUNTAINS.

Jl. VIEW SOUTHEASTWARD TOWARD THE HEAD OF GOLDEN CRbEK,
GEOGRAPHY BELIEF. 11

seem to have so far reduced the space between them as to interlock in a rather 

extensive flat at an altitude of approximately 1,500 feet, where-a few scattering lakes 

indicate the indefiniteness of the drainage.

From the White Mountains and from the commanding ridges of the Fairbanks 

region can be seen a group of hills 50 miles or more to the west, which rises abruptly 

from the indistinct level of its surroundings so that it forms the most conspicuous 

topographic feature in all the far western section of the Yukon-Tanana country. 

This group resolves itself on nearer view into the main divide between the Yukon 

and Tanana drainage systems and two prominent extensions from it to the north 

Lynx Mountain, a ridge several miles in length, and Wolverine Mountain, a massive 

peak which gives to the Rampart region a maximum relief of over 4,000 feet with 

reference to the level of the Yukon at Rampart.

This portion of the divide contrasts strongly with that immediately to the east. 

It is higher, sharper, and rougher, extends in a northeast-southwest direction with 

a minimum altitude of about 2,000 feet, and separates with no indefiniteness the 

waters which flow to the north and tq the south toward Yukon and Tanana rivers. 

Long, rough, lateral spurs extend northward toward the Yukon, and their steep 

sides are deeply cut until there is presented a repetition of sharp spurs separated by

deep narrow canyons, which has justified the name "Troublesome country," commonly applied to a part of this region. South of the divide there is less complexity. 

Long, more gradually sloping ridges separate the more open valleys and merge 

finally into the extensive flats of Tolovana and Baker valleys. This difference in 

topographic expression so frequently observable on the northern and southern sides 

of the Yukon-Tanana country is here in the narrower space between the two rivers 

brought thus into sharper contrast.

The name Lynx Mountain has been applied to the southern end of a ridge about 

30 miles southeast of Rampart, which extends northward from the main divide a distance of about 5 miles, has an altitude of approximately 4,000 feet, and is topographically distinct from its surroundings. The outline is irregular, developing in places 

into rugged, angular points. The upper slopes are steep and have furnished much 

material for the extensive accumulations of talus below. Along the greater part of 

the eastern base they plunge deeply into narrow canyons. Toward the southern 

end of the eastern base, however, the undulating surface of the main divide roughens in proximity to the ridge, and throws a wave-like prominence- high up along 

the slope, the brown moss-covered surface of which contrasts strongly with the 

rock-strewn slopes above. Off to the east is the even surface of the broad divide. 

The southern termination of the ridge and a part of the western base are flanked by 

a slightly concave graded slope, the even surface of which is marked by ripples of 

fine rock waste. As the main divide extends round the southern end of the ridge 

the drainage is mostly toward the Yukon, and numerous tributaries of Hess Creek 

drain northward from both sides.

Wolverine Mountain is the crowning point of a bulky mass in the main divide, 8 

miles west of Lynx Mountain and about 12 miles southeast of Rampart. It has an 

altitude of approximately 4,640 feet and towers several hundred feet above adjacent 

parts of the ridge. The western slopes descend with steep but more or less regular 

grades to valleys which carry the drainage toward the Tanana. The northern slopes 

are steeper. Sharp spurs with a concave outline plunge in divergent courses toward 

the valley 2,000 feet below and divide into minor steeper spurs which buttress the 

mountain side. The spurs become more rounded and more divided toward the base 

and extend thence northward with more gradual slopes about 1 mile to the main 

drainage line. The edges of the upper spurs are shattered into piles of fragments, 

and the debris-laden slopes of neighboring spurs steeply intersect to form the gulches 

which furrow conspicuously the northern face.
12 GEOGRAPHY AND GEOLOGY OF RAMPART REGION.

DRAINAGE.

The drainage systems are represented on the accompanying map in various stages 

of incompleteness, but with sufficient detail to show their general relations. Tolovana River, tributary to the Tanana, with its long and widely divergent branches, 

occupies the central and largest part of the field. On the east Beaver Creek in flowing to the Yukon follows a peculiar V-shaped course between tributaries of the 

Tolovana. On the north and west are Hess and Minook creeks flowing west and 

north respectively at right angles to each other to the Yukon, while in the southwest the short irregularly fan-shaped system of Baker Creek carries to the Tanana 

the drainage from the southern slopes of the main divide.

Tolovana River has several far-reaching tributaries which approach closely the 

Birch Creek and Fairbanks regions on the east and the Rampart region on the west. 

On the north they drain a large area between the systems of Hess and Beaver creeks. 

Chatanika River, which is the most important tributary from the east, has its 

sources far to the northeast opposite the headwaters of Birch Creek. It enters 

the southeastern portion of the area and is closely identified with the Fairbanks 

region since Cleary Creek, an important gold producer, is.a tributary. The stream 

is comparatively straight and flows southwest toward the Tolovana. About 50 miles 

below the source, near the mouth of Cleary Creek, it is comparable in size with Little 

Chena.near the mouth of Fish Creek, having a width of TOO to 200 feet, and at ordinary stages of the water it is easily fordable on foot. The valley is open and of low 

grade and the stream keeps mostly to the steep northwestern side. On the southeast 

long lateral spurs from the distant ridges merge gradually into the flat valley. The 

tributaries are small and short. The valleys of those from the north west are narrowly 

V-shaped; those from the southeast are more open and their stream, flats grade 

gently into that of the Chatanika. Sixty miles to the west another tributary of the 

Tolovana, Goose Creek, receives the drainage from the deeply furrowed slopes south 

of Lynx Mountain and flows in a northeasterly direction until it almost breaks in 

upon the tributaries of Hess Creek, when it bends gradually to the south and southwest to form an important tributary of the main stream. There are several streams 

between Beaver -and Hess creeks, which flow in narrow V-shaped valleys southwestward toward the Tolovana. These probably unite to form tributaries of considerable size before reaching the lower valley.

' The valleys of all the tributaries coalesce finally into a flat which forms a great 

embayment extending northeastward from the river's mouth far into the hill country 

toward the Yukon. The surface of this flat is partly covered with large areas of 

grass and is flecked with lakes, some of which are of considerable size. Patches of 

timber run out into it from the lower slopes of the ridges and dark lines of timber 

crossing it indicate the drainage lines, where streams flow inconspicuously with a 

deep, sluggish current in channels lying 20 feet or more below the even surface.

Beaver Creek has a peculiar relation to the drainage system of the Tolovana. It 

flows with the tributaries of the latter as if it were one of them and then turns northward from among them to the Yukon. It heads far to the northeast opposite the 

headwaters of Preacher Creek, flows southwest close along the eastern base of the 

White Mountains in the same direction as the Chatanika, but about 15 miles farther 

to the west, turns sharply round the southern termination of the mountains, flows 

northeast along their western base nearly parallel with its former course to 

Yukon Flats, and crosses this great lowland in a circuitous course north and west to 

the Yukon. The length of the southwestward flowing portion is probably at least 

30 miles; that of the northeastward flowing portion is much greater. The distance 

from the mouth of the creek along the many wanderings across the Flats to the point 

where it emerges from the hills is reported to be nearly 200 miles. Where crossed 

by the Survey party at two localities east and west of the White Mountains the creek
GEOaEAPHY DRAINAGE. 13

. is comparable in size with Chena River a few miles above the point where it is joined 

by West Fork. The stream has a width of 200 to 300 feet or more at ordinary stages 

of the water and is easily fordable on foot. The volume of water is at times large 

enough to permit prospectors to travel downstream in rafts from a point about 5 

miles above the sharp bend round the White Mountains, but on account of the shallowness of the water at the riffles considerable difficulty is probably experienced in 

this method of navigation. The creek meanders in a low-grade open valley. Above 

the bend the stream keeps close to the eastern base of the White Mountains and the 

valley is mostly on the eastern side where it extends back flatly nearly 2 miles to the 

base of the gradually sloping ridges. After rounding the southern termination of the 

White Mountains, however, the valley contracts to a width of about one-fourth of a 

mile, and flows for about 4 miles between the narrow ridge of the White Mountains 

and the ridge of the same height which extends northward from the plateau-like 

country to the southwest. Rounding the northern termination of this latter ridge the 

stream turns to the left in a northerly course and then to the northeast again to flow 

in wide meanders through a beautiful flat valley that is limited on the east by the 

broad slopes of the White Mountains and on the west by a steep ridge, which becomes 

more broken and more prominent toward the northeast, in harmony with the increasingly imposing character of the stream, which flows closely along its eastern 

base.

Most of the tributaries of Beaver Creek in the portion of the valley traversed by 

the Survey party are small. Two tributaries drain the southern part of the White 

Mountains, and one of .these has been called, for purposes of description, Fossil 

Creek, from the occurrence of fossiliferous limestone pebbles in its valley. The 

single narrow limestone ridge which terminates the White Mountains is accompanied farther east by a parallel ridge of shorter southern extent. The view from 

this ridge shows between the two a low-grade valley 2 miles wide, extending northeastward a distance of nearly 10 miles, drained by a stream which flows along the 

western side close to the base of the limestone ridge. From the base of the ridge on 

the east broad flat spurs separated by open depressions so shallow as hardly to be 

noticeable extend westward to the stream. On close examination the apparently 

continuous valley is seen to be composed of two parts a lower, drained by a stream 

which seems disproportionately small for the size of the.valley, and which has its 

rise in a few small stagnant ponds strung longitudinally along its course about 5 

miles from Beaver Creek, and an upper, drained by a stream of about the same 

length, which runs at first southwestward, in line with the stream of the lower portion of the valley, and then turns abruptly westward toflpw to Beaver Creek through 

a narrow canyon which interrupts inconspicuously the continuity of the 'limestone 

ridge.

This upper part of the valley has been reduced somewhat below the level of the 

lower part, but not to an' extent appreciable in a general view of the valley. The 

case is one of stream diversion where a minor tributary of the Beaver has cut 

through the limestone ridge and diverted to itself the waters of the upper portion of 

a valley which used to drain southwestward along the eastern base of the limestone 

ridge all the way to Beaver Creek. The diversion of the drainage from the upper 

valley has weakened the stream which occupies the lower portion of the valley, and 

its forceless character is indicated by the string of small ponds along its present 

headwaters.

The tributaries of Braver Creek from the east and south enter through open flat 

valleys. The valleys of tributaries from the west become more canyon-like toward 

the northeast, and there are none of importance until Victoria Creek is reached. 

This creek is reported to be 50 miles or more in length and to flow in its lower part 

in a comparatively narrow canyon. The branching headwaters are small streams, 

colored brown by vegetation, which flow in valleys, whose wide sweeping slopes are
14 GEOGEAPHY AND GEOLOGY OF EAMPAET EEGION.

mostly bare of timber. On this creek, close to its junction with Beaver Creek, 

near the southern limit of Yukon Flats, some prospecting was being done in the fall 

of 1904.

Hess Creek is about 60 miles long, flows in a general westerly direction, and enters 

the Yukon about 25 miles above Eampart. Its headwaters are closely associated 

with those of Beaver Creek and the Tolovana. Its northern tributaries penetrate 

far into the narrow belt of ridges between it and Yukon Flats. The southern tributaries head far back in the main divide opposite those of the Tolovana, and in places 

are most closely associated with those of the latter stream ; westward near the Rampart region they interlock with the tributaries of Minook Creek. This stream, where 

crossed by the Survey party in 1904, was nearly the size of the Chatanika and was 

easily fordable on foot. It flows meanderingly in a fairly flat valley with a maximum 

width of perhaps 2 miles. The main valley is limited on the north generally by 

rather steep slopes. The southern side of the valley has apparently more tributaries 

and has been much dissected by them into numerous long ridges which extend in 

most irregular courses northward from the main divide. The valleys of these southern 

tributaries in the area between the headwaters and Lynx Mountain are often open 

and form large, ill-drained spaces where lakes are common. .

The most important tributary in the vicinity'of Rampart is Troublesome Creek. 

It heads in the main divide opposite the headwaters of the Tolovana and flows in a 

general northerly direction a distance of 30 miles or more to Hess Creek. The 

valley is of the canyon type, with a narrow flat at the bottom, over which the stream 

flows in a meandering course. This stream is probably comparable in size with 

Minook Creek. Our knowledge of it is confined mostly to the upper portion of the 

valley, where it is formed by minor tributaries from the east and west, which drain 

the slopes of Lynx and Wolverine mountains and the portion of the divide between 

these prominent points. They are deeply incised within the inclosing ridges and 

their minutest ramifications are to be found in the steep, narrowly V-shaped gulches 

which furrow the northern slopes of the divide and the flanks of the two imposing 

prominences. The heads of the minor valleys are in some cases open park-like spaces 

of small extent, which contrast strongly with the inclosing rock-strewn slopes.

The two most important tributaries in this upper part of the valley are Gazzam or 

Quartz Creek from the east and Quail Creek from the west. The first is a small creek 

which heads in the main divide near the southwest base of Lynx Mountain and 

flows at first northwest and then west a distance of about 5 miles to Troublesome 

Creek. The upper portion of the valley is open and is formed on the east by the 

beautiful slope at the base of Lynx Mountain; the western side of the. valley is steep 

and a few small tributaries are received from V-shaped canyons. The valley narrows 

about 2 miles below the head to a steep-walled canyon deep within the ridges of 

either side. Quail Creek is the most important tributary of the upper valley. It is 

formed by two forks from the south and west, which join about a mile west of the 

Troublesome. The southern fork receives the drainage from the divide and the 

eastern flanks of Wolverine Mountain. The western fork heads opposite Hoosier 

Creek and flows in an easterly direction a distance of about 5 miles to the junction of 

the forks. The eastern part of the valley has a gradual northern slope, while the 

southern side is comparatively abrupt. Toward the headwaters the valley is more 

symmetrical. There are many small tributaries from the northern slopes of Wolverine 

Mountain, and most of these enter through narrow valleys. As on Hess Creek, 

benches are developed in places along the sides of the valley at a height of 400 feet 

or more above it.

Minook Creek, tributary to the Yukon, is the most western of the important 

streams in the Yukon-Tanana country, and shares with Baker Creek, tributary to the 

Tanana, the prominence resulting from the occurrence of gold in the drainage areas 

of these two streams. Minook Creek, which lies about 12 miles west of Troublesome
GEOGKAPHY DKAINAGE. 15

Creek, heads at a point about 25 miles south of Rampart and flows in a northerly 

course through a narrow valley. West of the valley a steep slope rises to a height of 

1,000 feet or more above the stream. The eastern side of the upper portion of the 

valley is formed by a similar slope. In the lower part of the valley, however, the 

eastern slope is formed by the abrupt stream ward-facing slope of a flattened area 

which, where it breaks off to the stream, has an elevation of about 500 feet above it 

and slopes gradually upward toward the base of the hills and widens to the north 

until it attains a maximum width of about 3 miles. The significance of this flattened 

area or high bench, as it is called by the miners, with reference to Minook Creek, 

will be considered elsewhere in this report. It suffices here to say that it is one of 

the products of valley development in the region, and that its relation to Minook 

Creek is similar to that of the small, low benches which occur in the valley of the 

present stream, being really a portion of an older valley in which the present canyon 

has been cut. The most important tributaries from, the east are Hunter, Little 

Minook, Little Minook Junior, Hoosier, Florida, and Chapman creeks. The most 

important from the west are Ruby, Slate, and Granite creeks.

Minook drainage in general may be described as a system deeply sunk within the 

inclosing ridges, draining with the ramifying headwaters of the eastern tributaries 

the rough country in the vicinity of Wolverine Mountain, to the south interlacing 

closely with the headwaters of Baker Creek and to the west draining a narrow strip 

of country extending backward only a few miles from the main valley.

The Baker Creek system is of a different character. Baker Creek is formed by 

the union of tributaries which converge from an irregularly fan-shaped area extending to a distance of about 20 miles north of. Tanana. The main stream flows for the 

greater part of its course in a southeasterly direction close to a low ridge which 

limits the valley on the south and then turns abruptly through the ridge to flow for 

the rest of its course southwest toward the Tanana. The flat valley, known as Baker 

Flats, extends northward 6 miles or more to the southern limit of the hill country 

and forms a feature similar in character to Tolovana Flats.

The tributaries are mostly from the north,- and- the most important of these 

northern tributaries or their branches are the Hutlina, Pioneer, Eureka, Glenn, 

Rhode Island, Omega, and Thanksgiving creeks. They rise to the east opposite the 

headwaters of the Tolovana, farther west receive the drainage from, the southern 

slopes of Wolverine Mountain, and still farther to the west drain the southern slopes 

of the main divide opposite the headwaters of Minook Creek. They flow in southwesterly courses and beyond the edge of the hills partly unite and partly find their 

way by indefinite courses to Baker Creek. They exhibit at first the characteristics 

of the streams of the northern slope, flowing deep below the inclosing ridges in 

narrow steep-walled canyons. The valleys widen rapidly, however, and their lower 

open parts merge with gentle gradients into Baker Flats while the long even-topped 

ridges between them descend somewhat more abruptly to the same level.

A most striking detail of form development which finds constant repetition is the 

unsymmetrical cross section of the Alleys. The southeast side descends steeply a 

distance of several hundred feet to the stream, while the northwest side rises gradually for a distance of a half mile "or more back from the stream and then ascends 

somewhat more steeply to the ridge line and descends abruptly to the neighboring 

parallel stream. Benching has been associated with this unsymmetrical development of the valleys, and the gradual northwestern slopes have afforded conditions 

favorable for the retention of gold-bearing gravels at elevations of 200 to 300 feet and 

more above the present level of the streams.

The main features of the Baker system are the long, even-topped ridges extending 

southward from the main divide, inclosing the unsymmetrical valleys, the gradually 

sloping benches of the lower valleys, and, beyond the terminations of the ridges 

and the benched areas of the knyer slopes, Baker Flats.
16 GEOGRAPHY AND GEOLOGY OF RAMPART REGION.

VEGETATION.

The high ridges are mostly bare of trees and covered only with the brownish vegetation of the tundra. The lower ridges are often covered with a dense growth of 

scattering spruce. The timber, however, is confined generally to the main valleys, 

where it is most thickly concentrated in scattering bunches along the water courses. 

Spruce is the most important tree and frequently attains a diameter of two or more 

feet. Birch and poplar are associated with it, and in the larger valleys there is a 

small proportion of tamarack. Willows and alders grow abundantly near the 

streams. There is said to be good timber in the lower valley .of the Chatanika, and 

some good timber is known to occur in Tolovana Valley. Beaver Valley, where 

crossed by the Survey party, contained but a small amount of timber suitable for 

mining purposes, and the part of the valley observable from the surrounding hills 

showed but small areas of timber. The.low ridges forming the eastern side of 

Beaver Valley east of the White Mountains present in places the appearance of a 

well-timbered country, but are in reality covered only with a thick growth of small 

spruce. The upper valley of Hess Creek and the open valleys of its tributaries contain also abundant small spruce with-some larger timber near the streams. The valley of Minook has contained considerable timber of sufficient size for mining purposes, 

but there is only a small amount of such timber left. The valleys of the southern 

slope facing Baker Flats contain but little timber of large size, and thus far the 

resources of Hutlina and Baker A'alleys, where there is said to be some good timber, 

have been but little utilized. The main supply for the Rampart region must come 

from Yukon Valley or be imported, and lumber in 1904 was worth as high as $100 a 

thousand. Timber for fuel purposes is abundant in most of the valleys and on the 

lower slopes.

Feed for horses can generally be found on the sunward-facing slopes of the main 

valleys, where there is often a luxuriant growth of grass among the birches. Grass 

grows abundantly on portions of the high bench near Rampart, and there are large 

grass-covered areas in Tolovana Flats. Vegetables can be grown easily, and at Hot 

Springs, a locality near the Tanana, they are raised in large quantities and sold to 

the miners. The Government has an experimental farm on the north side of the 

Yukon opposite Rampart. Blueberries and cranberries are almost always to be 

found in abundance, and at one locality in the Rampart region currants and red 

raspberries were, being preserved for winter .consumption.

GEOLOGY. 

GENERAL, FEATURES.

The bed rock in the western part of the Yukon-.Tanana country, while including 

some small areas of metamorphic schists, is made up mostly of sedimentary rocks, 

less metamorphosed than the schists lying to the east. The prevailing color is black 

from the large amount of carbonaceous matter present in the slates, but associated 

white limestones often become prominent and in the White Mountains through their 

color and topographic development emphasize the lithologic change from the 

quartzite-schists, quartz-mica-schists, and gneisses of the Fortymile, Birch Creek, and 

Fairbanks regions to the younger-looking rocks of the western areas. A considerable variety of igneous rocks occur in the vicinity of Rampart, and greenstones are 

common throughout the area. The general strike of the rocks is northeast and 

southwest. They have everywhere been closely folded and the folding seems to 

have been most intense in the Rampart region, where there has been further deformation of the rocks, resulting in some cases in brecciation.
GEOLOGY. 17

STRATIGKAPHIC SUCCESSION.

The variety of the rocks and the close folding which they have undergone have 

rendered difficult the attainment of definite knowledge regarding their sequence, 

thickness, and contact relations. Their areal distribution, so far as observed in the 

narrow belt of the country traversed, is shown on the accompanying geologic map 

(PI. I), and the provisional order of stratigraphic succession is outlined in the following tabular statement:

Provisional tabular statement of stratigraphy.

Age.

Pennsylvania!! or Permo-Carboniferous.

Pre-Devonian .........

Formation name.

sibly other formations.

Birch Creek.)

Contact relation.

Paleozoics.

Lithologic character.

solidated clays.

slates.

thin siliceous beds.

stones, greenstones, quartettes, and 

slates.

Conglomerates and fine fragmentals, 

slates, and interbedded limestones.

Cherts, slates, and greenstones.

Quartz-mica and garnetiferous schists. 

Quartzite schists.

The oldest rocks are believed to be the schists, predominantly quartzite-schists, 

which occur southeast of the White Mountains in the ridge which forms the western 

limit of Chatanika Valley, and the garnetiferous quartz-mica-schists with associated 

highly crystalline limestones which occupy a small area in the Rampart region 

along Minook Creek in the vicinity of Ruby Creek. Their age is unknown, and 

they are referred in this report to the pre-Devonian. The rocks from the White 

Mountains westward, inclusive of the Rampart region, are mostly of Paleozoic age, 

and the evidence of the few fossils collected indicates the presence of both Devonian 

and Carboniferous rocks. There is a possibility that some of them are Silurian, but 

in the absence of positive criteria for their further separation only two divisions 

have been made. Those regarded as Devonian include a variety of rocks differing 

greatly in lithologic character and occurring throughout most of the area. Cherts, 

slates with interbedded coarser fragmentals, greenstones, limestones, and quartzites 

are the most characteristic types. Along the northern edge of the hill country and 

at one locality south of Hess Creek fossils determined as Carboniferous were 

obtained, but the extent and contact relations of the Carboniferous rocks have not 

yet been determined. The rocks provisionally classed as Cretaceous are of doubtful 

age. They occur on Wolverine and Lynx mountains. On Wolverine Mountain 

fragmentary fossils were found which indicate an age not older than, the Lower 

Cretaceous. The Kenai rocks occur along the Yukon and to a short distance up the 

valley of the Minook. High gravels, regarded as Pleistocene, are found locally 

along the larger streams to heights of 400 to 500 feet above them. The present 

valleys are occupied by stream gravels covered generally with muck and moss, and 

the thickness of the entire deposit, so far as developed on the gold-producing creeks, 

rarely exceeds 20 feet, but exceptionally is of much greater depth.

Bull. 280 06 2
18 GEOGEAPHY AND GEOLOGY OF EAMPAET EEGION.

SEDIMENTARY AND METAMORPHOSED FORMATION'S.

PKE-DEVONIAN.

The most characteristic rocks in the eastern portion of the Yukon-Tanana country 

are gneisses, quartzite-schists, quartz-mica-schists, garhetiferous and hornblende 

schists, and crystalline limestone. In the Fortymile region the last three types 

predominate and have been called a by Spurr collectively the Fortymile formation; in 

the Birch Creek region and in the.recently developed Fairbanks region the quartziteschists and mica-schists, with occasional thin interbedded highly crystalline limestones, constitute the most common rocks and have been called by the same author 

the Birch Creek formation. They are considered by him older than the Fortymile 

schists. The age is not known, and for the purposes of this report they are both 

referred to the pre-Devonian.

The western limit of the large areas of these highly metamorphosed schists is in 

the ridge limiting on the northwest the valley of Chatanika River. The ridge is 

formed of the typical schists with some schistose limestone and graphitic schists, 

and like the rocks in the Fairbanks region the dip is generally low, a common attitude and one indicating not necessarily simplicity of structure but oftentimes a 

folding so extreme that the rocks have been Jolded upon themselves until the dips 

are often nearly horizontal. The first indication of a change in lithologic character 

was found in the occurrence a few miles nearer the White Mountains of a feldspathic 

schist, and then about 3 miles farther to the northwest overlooking Beaver Valley 

outcrops of a rather coarse-grained, greenish, impure, feldspathic quartzite showing 

no schistosity and dipping steeply to the Avest. The northwestern limit of the old 

schists is apparently somewhere in the intervening densely spruce-clad areas.

No more schists -were Observed until reaching the Rampart region, where on 

Minook Creek a small area of garnetiferous quartz-mica-schist with associated marbles occurs. This is apparently best developed on Ruby Creek, where the garnets 

of the schist accumulate rapidly in the sluice boxes. This formation of schist and 

limestone crosses the Minook at Hopkins Bridge with a northeast strike and a low 

dip to the southeast. Eagle Rock, about 1 mile below the bridge, is a bluff, 100 feet 

or more in height, composed of highly crystalline, banded limestone. There are 

minor folds and a' general low dip to the north. Although the area is small and the 

marbles resemble somewhat other crystalline limestones in the vicinity .they are so 

much more highly metamorphosed than any of the other rocks and are so closely 

associated Avith garnetiferous schists which are not known to occur elsewhere in the 

region that both the limestone and the schists stand in contrast to the adjacent 

rocks. The contact relations were not observed, but these rocks are believed to be 

unconformable with and older than the adjacent rocks to the north and south. 

Their resemblance to some of the schists and marbles of the Fortymile region is a 

striking one. They apparently strike off northeast under younger rocks.

No rocks were observed in the areas between.these two occurrences of schist which 

suggest a correlation. Further investigation may reveal the horizontal equivalency 

of some of the highly metamorphosed schists with less metamorphosed rocks of 

known age, but all that it seems possible to do at present is to place them by themselves and call them pre-Devonian.

DEVONIAN.

Between the two areas of schists above described, the one the westward extension 

of the schists of the Fairbanks region, the other a small area the limits of which 

are not yet known, are the rocks most of which are regarded provisionally as Devonian. The bulk of the formation, as already mentioned, is made up of cherts, slates

« Spurr, J. E., and Goodrich, H. B., Geology of the Yukon gold district, Alaska: Eighteenth Ann. 

Kept. U. S. Geol. Survey, pt. 3,1898, pp. 140-155.
GEOLOGY DEVONIAN. 19

with alternating beds of conglomerate, arkose, and quartzite, limestones, and large'ly 

tuffaceous greenstones. These rocks may be roughly divided into at .least two groups 

according as cherts, slates, greenstones, and conglomeratic rocks, or massive limestones with greenstones, slates, and quartzites predominate. It is believed that those 

forming the first division are older and it may become advisable on more detailed 

work to make a separate formation of them. The term " Rampart series " has been 

usedbySpurr« in grouping similar rocks occurring in other parts of the YukonTanana country. In those areas, however, diabase, tuffs, and green slates are most 

abundantly .developed, and carbonaceous slates and limestones, although frequently 

present, are of minor importance. In the areas under consideration, while the greenstones are found throughout, black slates, cherts, and massive dark- and light-gray 

limestones are more common and more strikingly characteristic of the formation. A 

section of these rocks is encountered in traveling from Chatanika Elver northward 

to the southern edge of Yukon Flats, a distance of about 60 miles, and this section, 

although incompletely studied, has afforded some material regarding the structure 

and age of the rocks which compose it.

' The general strike in the southern part of the section is about N. 50° B. and it is 

instructive to note that the direction of structure which is so strongly emphasized 

topographically in the Alaska Range is here repeated. In the northern part of the 

section the strike is more nearly east and west. The rocks are closely folded and in 

most cases their attitude is nearly vertical. There is a distinct symmetrical arrangement with reference to a northeast-southwest axis, arrd, so far as our present knowledge extends, this symmetrical disposition of the rocks seems to be .a fact of importance in regard to their structure and succession. This repetition is most noticeable 

in the occurrence of limestone. The White Mountain limestones with associated 

greenstones, flanked on the southeast by red and black_ slates and prominent masses 

of impure quartzite, rind a repetition 1.5 miles to the north in another limestone belt 

less conspicuous topographically than that of the White Mountains, with a similar 

association of rocks and flanked also on the northwest by similar slates and quartzites. 

The rocks of the middle portion of the section are slates, greenstones, and cherts, 

and, although the relations are not clear, there are two main areas of cherts about 3 

miles apart with black, purple, and greenish slates and some greenstones in the intervening space. In passing northward from the northern belt of cherts toward the 

northern belt of limestones there are conglomerates containing abundant chert 

pebbles. In passing southward toward the limestones of the White Mountains there 

are also chert conglomerates with pebbles an inch or more in diameter associated 

with finer rocks containing grains of chert and fragments of. slate. Black slates are 

also common and thin beds of conglomerate are interbedded with them. The slates 

are closely succeeded by the limestones on either side and, although the direct relation of the two was not observed, it is believed that the limestones are younger than 

the rocks above described. The quartzite flanking the limestone on the north, 

which is very similar to other quartzites apparently interbedded with the limestones, 

contains occasional fragments of chert and it seems best for the purposes of this 

report and until further knowledge is available to consider the flanking slates and 

quartzites as partly of the same age as the limestones and partly younger.

Fossils found in the limestones of the White Mountains have been determined as 

characteristic of early to . middle Devonian, and some of them are possibly of 

Silurian age;, but the stratigraphic association makes it probable that all the remains 

belong approximately to the same horizon and the determinations point more definitely to the Devonian. No fossils were found in the limestones of the northern 

belt, but the rocks and their associations are very similar and no reasons were found 

for assigning them to a different position.

aSpurr, J. E., Eighteenth Ann. Kept. U. S. Geol. Survey, pt. 3, pp. 155-169.
20 GEOGRAPHY AND GEOLOGY OF -RAMPART REGION.

If this interpretation of the section is correct the purple, green, and black slates 

and cherts with associated greenstones are probably the oldest rocks in the region 

and may possibly belong to the Silurian, but from the fact that wherever they have 

been found to occur they are intimately related to limestones, which, where determinable, have been found to be Devonian, it seems best at present to call them all 

Devonian.

The contact relations of these rocks with the rocks to-the north and south of them 

are not clear. On the south the red and black slates with massive greenish quartzite 

form a ridge just west of Beaver Creek between Beaver Creek and the White Mountains, and outcrops of the quartzite occur sparingly southeast of Beaver Creek, where 

their attitude is nearly vertical. At the northern end of the section the relations are 

different. Fossils determined as Pennsylvania!! or Permo-Carboniferous were found 

in a low, outlying ridge overlooking the Flats, and across a narrow valley on the south 

are black slates and cherts at the base of a high ridge, the topmost points of which 

are quartzites containing occasional chert pebbles interbedded with red and black 

slates and some dark limestones. All of these are regarded as Devonian.

The evidence at hand seems sufficient only to justify the statement that in the 

section from Chatanika River to Yukon Flats there is a large area of closely folded 

rocks, mostly of Devonian age, flanked on the south by highly metamorphosed schists 

and on the north by slates partly similar lithologically to the Devonian slates, but 

containing Carboniferous fossils. Any interpretation of the section on the basis of 

our present knowledge is open to objections. For example, dips were observed in 

the White Mountains which indicate a local anticlinal structure, but the folding has 

been so close that only more detailed studies of the structure supported by more 

than the fragmentary paleontologic evidence at our disposal will afford the basis for 

a reasonable approximation to the truth. The present hypothetical interpretation 

of the section is regarded as a temporary basis only, the first at hand, perhaps, for 

the preliminary description of the material occurring in this area. Whether it shall 

be found sufficiently strong to be given the dignity of a permanent basis in the 

explanation of the structure or must be replaced by one better able to "bear the 

accumulating weight of evidence is, for the purposes of this report, immaterial.

Passing to the Rampart region there is found a variety of rocks like those already 

described. The disturbance which they have undergone has been greater and intrusion by igneous material more active. Folding has been intense, many of the rocks 

have been greatly sheared and in some cases brecciated by the forces to which they 

have been subjected. A section northward from Baker Flats to Rampart is shown

in PI. I. The strike of. the rocks is nearly east and west. The garnetiferous micaschists and marbles of Ruby Creek, considered as pre-Devonian, are followed on the 

north by cherts and greenstones and on the south by rocks including slate, chert, 

sheared chert conglomerate, fine-grained rocks having the same composition as the 

chert conglomerate and also sheared till they have been rendered schistose, massive 

quartzites, and siliceous limestones, in places much brecciated. Here, also, the succession seems to be from chert and slates through chert conglomerate to fine slate 

and limestones.

There are other localities in the Rampart region where a partial succession has 

been observed. The main divide to the east of Lynx Mountain is composed mostly 

of chert flanked by chert conglomerate, and at one locality near the southeastern 

base of Lynx Mountain there are fine exposures showing at the base a conglomerate 

containing sheared chert pebbles several inches in diameter, changing gradually to 

alternating beds of finer material. At a locality not far from this gray slates were 

observed highly folded and cleaved and pitching eastward. These slates contain 

thin beds of quartzite a few inches to a foot or more thick which contain grains of 

chert.

In Troublesome Valley the succession seems to be the same. A section southward
GEOLOGY DEVONIAN. 21

between Troublesome and Hunter creeks shows greenstones, cherts, sheared chert 

conglomerate, and slates, with disconnected limestone masses in Avhich fossils determined as Devonian were found. The chert conglomerates are.frequently found in 

close association with the limestones, and at the .locality where Devonian corals were 

collected conglomerate with' chert and quartz pebbles is found in close association 

with the limestone, which also contains quartz pebbles.

Most of the rocks encountered in the Kampart region are a continuation along the 

strike of those occurring in the section from the White Mountains nearly to Yukon 

Flats. There are the same lithologic types, the same associations, and, so far as the 

meager fossil evidence is available, it corroborates the relationship of the rocks in 

the two areas.

Following is the list of fossils collected .by the party. The determinations Avere 

made by Mr. E. M. Kindle, of the United States Geological Survey:

Fossils from the White Mountains.

4 AP 240. This lot contains two corals, a Michelina and a Zaphrentis, neither of which 

is specifically deterniinable. Horizon probably Devonian.

4 AP 241. Favosites near epidermatus occurs in this collection indicating a horizon of 

Middle Devonian age.

4 AP 242. Specimens of a coral comparable Avith Favosites winchelli comprise the 

collection from this locality. Horizon probably middle Devonian.

4 AP243, 245, and 246. These several lots represent the same horizon. The fauna 

as represented in the collection comprises a single species of brachiopocl Gypidula 

of pseudo-galeatus. The horizon represented is either late Silurian or early Devonian, probably the. latter.

4 AH. 186. Includes only poorly preserved specimens of Cladopora. Probably of 

middle Devonian age.

4 AH 193. The fossils represented are Cytherella sp., Cladopora sp., and Ptilodictyaf 

cf. frondosa. The horizon is probably Silurian.

4 AH 194. Favosites near limitaris occurs in this lot, indicating a horizon probably 

near middle Devonian.

4 AH 195. Contains an undetermined Stromatopora. Age probably DeA'Onian.

N *

Fossils from the Rampart region.

4 AP 303. Two poorly preserved specimens of Aulacophyllum comprise this lot. The 

 horizon represented may be either Devonian or Silurian, so far as the evidence

from this material indicates. 

4 AP 317. Minute fragments of small corals in a breccia comprise this lot. Fossils

too fragmentary for determination of the age.

. CARBONIFEROUS.

At the extreme northern limit of the hill country, in a minor ridge bordering 

Yukon Flats, there are greenish, grayish, and black slates, Avith siliceous material, 

scattered fragments of Avhich Avere found to contain fossils indicating a Pennsylvanian 

or Permo-Carboniferous age. At another locality, about 15 miles to the soutliAvest, 

just south of Hess Creek, fossils also regarded as Carboniferous were found in soft 

black carbonaceous shales. At both localities the rocks are in close associationvon 

the south with cherts and slates, and it is possible that some of the cherts may be of 

Carboniferous age. All that can be affirmed at present is that in the northern part 

of the area there occur Carboniferous rocks, Avhose extent and relations to the rocks 

of Devonian age are not yet determined.

The following fossils, determined by Mr. George H. Girty, were collected at the 

two localities and the discussion of them is-quoted from his report.
22 GEOGRAPHY AND GEOLOGY OF RAMPART REGION.

Fossils from near Yukon Flats and from Hess Creek, Alaska. 

4 AH 213.

Stenopora, two sp. Rhombopora sp.

Fenestella sp. Productus ? sp.

Rhombopora sp. . Lima ? sp.

4 AP 270.

Fistulipora sp. Rhombopora sp. 

Stromatopora ? sp. Rhombopora sp. 

Coral sp. Spirifer n. sp. ? 

Fistulipora sp. Hustedia cf. H. compressa Meek. 

Fistulipora? sp.

' 4 AP 277.

Coral ? sp. . . Polypora ? sp.

Lithostrotion ? sp. Archimedes ? sp.

Fistulipora 3 sp. Prodnctus sp.

Rhombopora sp. Euomphalus sp.

The presence of the form identified as Hustedia compressa seems to show that lot 270 belongs in the 

Pennsylvania!!, perhaps in the Permo-Carboniferous. The ages of the other lots, although without 

much doubt being Carboniferous, are less certain. While probably no species is common to all three 

collections, yet in a general way the facies is much the same, and it is quite possible that all represent the same fauna. .

It will be observed that only in.one case have the forms collected been identified specifically. Jn 

many instances the material is too imperfectly preserved to admit of more than the genus being 

determined. In others the species are distinct from those, of the Mississippi Valley sections, and 

entirely new unless some of them have been described in European and Asiatic publications not 

included in my bibliography and therefore difficult of reference.

I have consulted freely with Mr. Bassler wherever the Bryozoa were concerned.

CRETACEOUS.

High up on the flanks of the Wolverine and Lynx mountains are black, rather massive, impure sandstones and shales. In the sandstones of Wolverine Mountain, 

which form great rock piles along the upper parts of the spurs at an altitude of over 

3,000 feet above the base of the mountain, were found fragments of dicotyledonous 

leaves and a part of an indeterminable bivalve. The shales, also, were found to 

contain a few obscure plant remains. The only positive result obtained is the fact 

that there are rocks occupying the highest parts in the area, which are at least as young 

as the Lower Cretaceous and far younger than the rocks of the lower slopes of Wolverine Mountain, \vhere limestones were found containing corals, the stratigraphic 

value of which is sufficient only to determine the age as either [Silurian or Devonian. 

They rest on the upturned edges of the older rocks and have themselves undergone 

considerable deformation. Just how much is to be included with these rocks has 

not been determined. The associated black, carbonaceous, slaty shales are like 

those closely associated with the rocks regarded as Devonian. The black, sandy beds, 

in which the fossils were found are unlike those observed elsewhere and resemble the 

Upper Cretaceous rocks which occur lower down the Yukon. They are entirely 

different from the Kenai rocks near Rampart and are referred provisionally to the 

Cretaceous. 8

TERTIARY. ^

Eocks determined as Kenai occur along the Yukon above Rampart and are found 

also for a short distance up the valley of Minook Creek, where they contain a small 

amount of coal. There are conglomerates, sandstones, and clays resting unconformably on the older rocks. The degree of consolidation is hardly sufficient in some 

cases to withstand the pick, and prospect holes have been sunk into this formation 

under the impression that the-material belonged to the stream deposits. These 

rocks are folded, but otherwise are little changed.
GEOLOGY IGNEOUS ROCKS. 23 

QUATERNARY.

The changes in elevation with reference to sea level which the Yukon-Tanana conntry has undergone have left at various altitudes benches, sometimes of considerable 

extent, which stand generally in a definite relation to the present drainage lines. An 

accompaniment of benching has been the deposition upon some of the benches of 

gravel deposits, part of which are regarded as of Pleistocene age. Benches are 

prominently developed along Hess Creek and its tributaries, along the Minook, and 

along the tributaries of Baker Creek. The deposits of the high bench of the Minook, 

approximately 500 feet above the present stream, are of interest with reference 

to the occurrence of gold in the tributaries of Minook Creek. The bench gravels of 

the Baker drainage have proved in some places to be of great economic importance. 

The description of these gravels and the deposits of the present streams is given 

elsewhere in this report in the account of the gold placers.

IGNEOUS ROCKS.

The eastern part of the Yukon-Tanana country is characterized by an abundance 

of intrusive and extrusive rocks of varied composition. There are several batholithic masses varying in composition from granite to quartz-diorite, with numerous apophyses in the country rock. Acid granitic rocks are abundant, and occur 

commonly in small dikes, some of which are comparatively fresh, while others have 

been rendered schistose along with the country rock. These become less abundant 

toward the west and seem to disappear. In the Birch Creek and Fairbanks regions 

the most common rock of igneous origin is biotite-granite. After crossing the 

White Mountains no rocks of igneous origin except greenstones were encountered 

until reaching the immediate vicinity of Rampart. That region has been an area 

of great igneous activity, in which granitic rocks and more'basic granular rocks are 

common, occurring as small intrusive masses and narrow dikes, and'their extrusive 

representatives are also to be found in small amount. The igneous rocks will not 

be considered in detail, and only such description will be included as seems necessary for the purposes of this report. They may be grouped roughly as granitic 

rocks with their surface representatives, monzonitic rocks, greenstones, and basalt 

with associated glass. The most characteristically developed of them are the greeiistones which occur throughout the area. The basaltic rocks so far as observed have 

but a limited distribution. .

GRANITIC ROCKS.

The granitic rocks are not of common occurrence. The most extensive mass 

observed forms a part of the summit of Wolverine Mountain, where it occupies an. 

area about 1,000 feet wide. It is a porphyritic, massive, gray rock composed chiefly 

of quartz, phenocrysts of orthoclase a half inch or more in diameter, considerable 

plagioclase, some biotite and hornblende, and a little pyroxene. The rock is finer 

grained toward the margin.- The slates in contact with it have been indurated and 

their fracture surfaces are flecked .with the products of metamorphism, chiefly 

andalusite.

A similar rock occurs west of the mountain near the saddle where the trail passes 

through the ridge to descend toward the Hutlina. This is also a gray porphyritic 

rock, but the porphyritic feldspars sometimes an inch or more in diameter have a 

tabular development. The proportion of pyroxene is greater, there is less quartz, 

and the composition of the rock is transitional to that of the monzonitic rocks. 

Rocks similar in composition to those of Wolverine Mountain occur also in Lynx 

Mountain along with monzonitic rocks, but their outcrops were not observed.

A siliceous rock occurs west of Minook Creek about 7 miles from Rampart- It is 

a finely banded, grayish-brown rock and has been complexly folded on a small scale,
24 GEQGKAPHY AND GEOLOGF OF RAMPAET REGION.

so that in a hand specimen most intricate' foldings may be observed. Brecciation 

has been common; and the. interstices of the fragments have been filled with ferruginous matter. The banding resembles sedimentation, but under the microscope 

the rock is found to be composed almost entirely of minute spherulites clouded with 

a very minute development of graphic intergrowths. The rock forms a sharply 

pointed prominent hill rising about 200 feet above the valley. Its relations to the 

surrounding rocks are not known, but small dikes of a rock composed essentially of 

quartz and feldspar phenocrysts occasionally occur in a fine-grained, partly graphic 

groundmass, and it is possible these are derived from the same magma.

MONZONITIC ROCKS.

The most common intrusive is a monzonitic rock which varies in color from dark 

brdwn to nearly black. It is a medium to fine-grained rock and the coarser varieties 

show abundant plates of reddish-brown mica, the most striking mineral present. All 

the minerals of this rock are fresh and include about equal proportions of an orthoclastic feldspar-and of plagioclase which is embedded in the irregular limpid mottled 

grains of potash feldspar, abundant pale-green monoclinic pyroxene, biotite, and a 

small proportion of olivine. Hypersthene occurs frequently, its small prisms often 

fringing the grains of olivine. There is some apatite and often much magnetite.

This rock occurs in Lynx Mountain and in the ridge at the head of Glenn, Rhode 

Island, and Omega creeks, where it forms a mass of considerable extent. The numerous small dikes of minette-like rock in the slates, from 1 foot to 3 feet thick, containing prominent plates of bleached. biotite and a large proportion of nearly colorless 

prismatic crystals of monoclinic pyroxene, are probably to be referred to this type.

The coarse granular type is similar in composition.and texture to the rock found in 

1902 by the Brooks party at one locality on the eastern side of the Alaska Eange, and 

this occurrence in the Eampart region is the only one thus far found in the YukonTanana country.

GREENSTONES.

The greenstones include serpentine, altered gabbro, diabase, basalt, and much tuffaceous material, and have frequently been intruded by fresh diabasic rocks. Some 

show clearly their mode of origin. Others are indefinite aphanitic chert-like rocks. 

They occur throughout the area from the White Mountains to Rampart. Their dark 

color contrasts strongly with the associated limestones of the White Mountains; they 

form the prominent ridge across Beaver Valley to the west of these mountains, and 

occur in the area between this ridge and the Flats. Farther west they become 

prominent in the ridge north of Hess Creek. In the Rampart region they form the 

bed rock in the lower part of Troublesome Valley and are the most widely distributed rocks in the lower valley of the Minook below the mouth of Florida Creek.

The greenstones are partly intrusive and partly extrusive to the rocks in which 

they occur. Those in association with the limestone are, so far as has been observed, 

parallel to the structure, and furthermore some of them are altered basalts containing numerous amygdules filled with calcite. Diabasic intrusives occur cutting the 

serpentine, and in the Rampart region intruding the Rampart slates.

A fresh olivine basalt occurs on Minook Creek about 1 mile above the mouth. On 

Hunter Creek, a short distance above the mouth, and apparently related-to the basalt 

in their occurrence, are volcanic glasses containing basic feldspar phenocrysts.

SUMMARY.

The greater part of the area is occupied by closely folded sedimentary rocks, and 

most of these are regarded as of Devonian age. Folding and metamorphism appear
GEOLOGIC SUMMARY. 25

to have been most active in the Rampart region, and some of the rocks have been 

rendered somewhat schistose, and others have been brecciated by the forces which 

have been at work. The igneous rocks include both intrusives and extrusives, and 

are present in great variety and abundance in the Rampart region.

Most of the gold-producing creeks tributary to Minook Creek from the east head 

in areas composed of slates, quartzites, feldspathic quartzites, chert, and sheared 

chert derivatives, and flow in the lower parts of their valleys through areas of greenstone, which are largely tuffaceous. The schistose, fine-grained fragmentals, alter- 

.nating with the slates and quartzites, form the greater part of the bed rock in the 

valleys of the streams tributary to Baker Creek. The same rocks strike off northeastward and occupy large areas in the valleys of the headwaters of the Tolovana, 

which were traversed by the Brooks party in 1902, and still farther in the same 

direction are found in the White Mountain section. There is no essential difference 

in the bed rock of the northern and southern sides of the divide in the Rampart 

region, except that the greenstones are confined mostly to the northern side in the 

lower part of Minook Valley below Florida Greet. Victoria Creek, a tributary of 

Beaver Creek, where prospects were reported in the fall of 1904, heads in an area of 

chert, slates, and greenstones, like those of the Rampart region.

The occurrence of gold has not been traced to a definite relation to any particular 

bed rock or to the quartz seams, which are rather common in the slates. Many of 

the dikes are more or less mineralized, and some of them are reported to carry values. 

The light-colored acid dikes of the Fortyrnile region, with their associated quartz 

veins, were not observed in the Rampart region. The slates contain generally a 

large amount of carbonaceous matter, and anthracitic material is common in some of 

the small quartz seams. Pyrite is of ten'found in both the slates and the quartz seams. 

On creeks where the conditions are apparently least complex the only rocks observed 

are the carbonaceous slates with quartz seams, which occasionally are a foot or more 

in thickness, and the monzonitic intrusives in the ridge about the headwaters. The 

nuggets have frequently a considerable quantity of quartz attached, and it seems 

probable that the gold has been derived from the small quartz seams. The only general fact which seems to emphasize itself is that the occurrence of gold in quantities 

of economic importance is limited to an area where deformation of the rocks has 

been intense and where there has been much igneous activity.
THE GOLD PLACERS.

By FRANK L. HESS.

GENERAL STATEMENT.

The placers of the Rampart region were studied by the Survey party for ten days 

during the first part of September, 1904. Every working claim was visited except 

those on Gunnison Creek, but in a number of cases where claims are worked only 

during the winter the operators could not be seen. Foot traverses were carried 

over the region and a sketch map was made (PI. III). The time allowed only-a 

hasty reconnaissance, though if it had been possible to know the dates of arrival and 

departure of the boats more time could have been put upon the study of the region. 

The miners met were universally generous, hearty, and hospitable, ready to help 

whenever possible with information or otherwise, and the work was thus made much 

more effective and pleasant.

The placer diggings near Rampart may be grouped according to the drainage systems to which they belong. The three general groups, Miriook Creek, Baker Creek, 

and Troublesome Creek, are separated by a divide having the general shape of a 

Y whose stem runs northeastward between the Minook and. Baker Creek drainage, 

whose left arm runs nearly northward from Wolverine Mountain, about 13 miles 

southeast of Rampart (PL III), and whose right arm runs nearly eastward, from 

the eastern base of the mountain. Between the arms, extending northward, is the 

"Troublesome country", as the region suYrounding the creek of that name is known 

from its steep, rocky ridges and deep, narrow valleys. Each group embraces 

only the diggings located on the creek that gives the group its name, or upon its 

tributaries.

In the Minook Creek group most of the gold-bearing creeks are on the east side, 

nearer the left-hand arm of the Y, only a few diggings being on the-west side of the 

creek. In the Baker Creek group the diggings now known are on the side nearer the 

Y, and in the Troublesome Creek group the only diggings known are on the west side 

of the creek, on branches flowing from the left arm of the Y". The extreme length 

of the area containing known gold-bearing localities is about 30 miles and its greatest 

width is about 12 miles, the total area being probably less than 350 square miles.

Winter prospecting is being done on Squaw Creek, a tributary of the Yukon about 

the size of Minook Creek, which enters the river nearly opposite Rampart.

The first placer claim in the Rampart region was. located and worked in 1896 on 

Little Minook Creek by F. S. Langford, though gold had been previously discovered 

by John Minook, a Russian half-breed, who seems to have sluiced out a small 

amount of gold, and for whom the creek was named. Some prospecting had probably been done along Minook Creek a number of years before. Since the first sys- 

.ternatic work in 1896 the region has been a constantly productive one. Though the

26 . ' - .
U.S. GEOLOGICAL SURVEY BULLETIN N0.28O PL.HI.

SKETCH MAP OF

RAMPART PLACER HKGION,

ALASKA

I HV Li.M. PHINDU":-VN'i> FHAN'K I,.HESS.

&\ I s Scale o/miles __'

i>'' N&N&Yy ^ravels known U> be gold bfariiijj 

Prodiirtjvo L'ftUl-bearmii gravels 

-I Trails
GENERAL STATEMENT. ' 27

amounts taken out have not been so large as those mined at places Jn the Klondike 

district or at a few of the claims near Nome, yet a number of creeks in this region 

produce a fair amount of gold. At first Little Minook and Hunter creeks were the 

only producers, and during 1897 no new ground seems to have been found, but in 

1898 a small amount was taken out of Quail Creek. Afterwards gold was discovered 

upon Little Minook Junior, Hoosier, Ruby, and Slate creeks .of Minook Creek 

Valley. In the meantime prospecting was carried on over the, divide on the south, 

and deposits along Baker Flats were discovered. In fact, each year has shown some 

new source of production, and it seems likely that more may still be found. -The 

output to the fall of 1904, from the best available data, was $1,112,000, and that for 

the year ending at the same time was about $232,900.

As Rampart lies only about 1 degree south of the Arctic Circle, the cold of winter 

is severe and the open season is comparatively short. During the early part of June 

thawing is generally so far advanced that some preliminary work and sluicing can 

be done. Cold snaps are likely to make the work intermittent at first, but the latter 

part of June and all of July and August can be depended upon for outside operations. Frosts are likely to occur the first part of September, though mining can 

sometimes be carried on during practically the whole month. In 1904 the sluice 

boxes froze up on the 5th of September, and after that date there were only a.few 

days on which sluicing could be done.

The surficial deposits are always frozen, and the limit of the frozen ground has not 

yet been reached, but there are channels in the frozen gravels through which water 

circulates freely at all seasons. Large masses of ground ice often occur in the muck, 

though none are found in the. gravels. The depth of the alluvial deposits sometimes 

exceeds 100 feet, but it is generally less than one-fifth of that amount.

The larger part of the mining has been carried on by drifting and- open cuts, 

depending on the season and the local conditions; but during the season of 1904 two 

hydraulic plants began active operations, and two more were under construction. 

Ordinarily, wherever the gold-bearing alluvials are of sufficient depth they are mined 

by drifting during the winter and the dirt taken Out is washed in the spring. In 

some cases the presence of water interferes very seriously with the drift mining and 

renders gravels otherwise workable comparatively valueless. Drifting can not ordinarily be carried on in the summer time, because the warm air melts the ground and 

causes it to cave. In thawing the ground for drift mining steam points have generally 

superseded wood fires, though the latter are still sometimes used.

During 1904 wages were $5 and board for a 10-hour day. This is equivalent to 

$6.50 to $9 a day, varying with the locality. The men who work for wages are 

generally strong and healthy and render a full equivalent for their pay.

The currency of the country, as in the early stages of most placer camps, is gold 

dust. The different values of the gold from the different creeks makes the fixing of. 

the price at which it should pass rather difficult, and the result is that, while some 

gold passes considerably be,ow its value, some passed at more than it is actually 

worth. The gold assays from $14.88 to over $19 per ounce, and passes at $15.50 to 

$18 per ounce.

MINOOK CREEK GROUP.

This group includes the placers of Minook CreekN and its tributaries within limits 

of 5 to 13 miles from Rampart. Most of the diggings, and much the richest so far discovered in .the group, are upon the east side' of the valley, and none have been found 

in the main valley above'the mouth of Slate Creek, 11 miles from Rampart.

The hills are generally rounded or flat-topped. The valleys are canyon-like, with 

steep walls 500 feet or more high, and benches are prominent features of the topography. The larger streams have cut their valleys down to a grade varying from 40 to 

80 feet to the mile. The watershed of Minook Valley is narrow on the west, sometimes
28 GOLD PLACEKS OF KAMPART REGION.

not over a half mile or a mile wide, and is probably at no place over 4 miles wide. 

On the east it is 5 to 7 miles wide through the greater part of the length of the creek.

The total production of the Minook Creek group has been about $702,600, of which 

$75,500 was produced during the winter of 1903-4 and $10,900 during the summer of 

1904, making a total for.the year of $86,400.

The surficial deposits are derived from the country rocks, mostly slate, quartzite, 

and greenstone, and reach occasionally a depth of over 100 feet, though usually much 

less than that, and there is generally a large proportion of muck.

MINOOK CREEK.

General description. Minook Creek empties into the Yukon just east of Rarnpart, 

and is about 25 miles long. Near its mouth it is a shallow stream 50 or 60 feet wide, 

with a flow of possibly 200 second-feet or 8,000 miner's inches. It flows in a northerly direction through a deep valley whose width varies from a few hundred feet to 

about a half mile. The creek receives a number of large tributaries from the east 

Hunter, Little Minook, Little Minook Junior, Hoosier, Florida, Chapman and a number of creeks whose names are unknown. From the west it receives Montana, Ruby, 

Slate, and Granite creeks and a few small tributaries. Granite Creek, about 17 miles 

from the Yukon, is the largest western tributary, carrying probably 30 to 40 secondfeet; Minook Creek carries perhaps 40 to 50 second-feet at the junction. These 

approximate estimates are given to convey some idea of the comparative sizes of the 

streams. -

Aneroid barometer readings by Mr. Arthur J. Collier « showed a descent of about 

760 feet from the "106 road house," about 1$ miles above Granite Creek, to the 

Yukon. As the distance is about 18 miles, these readings indicate a gradient of about 

42 feet to the mile. In the next 3£ miles above he noted a rise of 240 feet, showing 

a gradient of about 68 feet to the mile. According to Mr. M. E. Koonce, 6 of Rampart, the creek has a fall of about 40 feet in the vicinity of the mouths of Ruby and 

Slate creeks. Aneroid barometer readings of Mr. L. M. Prindle and the writer 

showed a somewhat higher grade for the central portion of the creek. It seems 

likely that Minook Creek has an average gradient of somewhat over 40 feet per mile 

from the Yukon to Slate Creek and a somewhat steeper gradient above Slate Creek.

Just below the mouth of Slate Creek the Minook spreads into a number of branches 

in a wide gravel flat. This flat, which is typical of many Alaskan streams, is probably due to a change in the grade of the creek. The stream here is unable to carry 

the gravels of the swifter water above, and so spreads them upon the flat. Here are 

found the so-called "winter glaciers," which sometimes last through the short summers. In 1904 a quarter or half acre of ice still remained when the September frosts 

occurred. This ice owes its origin to the fact that the channel which carries the 

water is greatly contracted by freezing in the fall. The resulting hydrostatic pressure 

cracks the ice and the water overflows and freezes. This process is repeated until a 

considerable thickness of ice is accumulated.

The valley is V-shaped in cross section, and the eastern slope is often benched, 

while the western is more abrupt and has remnants of benches at but few places. 

Five Avell-marked benches rise at irregular intervals above the floor between Little 

Minook Junior Creek and Hoosier Creek (fig. 1), the highest of which is about 500 

feet. These benches are features of much importance in both the physiography and 

economic geology of the region.' Important gravels cover the highest one, which 

lies on the east side of the Minook and extends from Hunter Creek to about a mile 

above Florida Creek. It will be described later. A small remnant of the same 

bench is found on the north side of the mouth of Montana Creek and another on

a Personal communication. In giving aneroid barometer readings their lack of reliability is recognized in all cases. 

b Personal communication.
MINOOK CREEK GEOUP. 29

the north side of the mouth of Ruby Creek. Other remnants are found on the 

north side>of the mouth of Chapman Creek, and at a point about 4$ miles above the 

Chapman on the same side of Minook Creek. The last two benches show no gravel. 

On the west side of the creek but few remnants of benches are found. One, about 

50 feet high, extends to a little above the mouth of Hunter Creek, and is probably 

an extension of a corresponding bench on the south side of the Yukon. It seems 

probable that all of the benches of Minook Creek may be more or less closely correlated with the benches of the Yukon. In the vicinity of the mouth of Slate Creek 

is a bench cut in the upturned slates and thin-bedded quartzites to a depth of 12 to 

.16 feet and covered by 4 or 5 feet of gravel and a foot or more of muck. No gravel 

has yet been found upon the benches of intermediate height, but further investigation may show its presence.

In its upper course the creek flows somewhat north of east for about 2 miles, and 

here the topography of its valley is altogether different from that of the lower part. 

The north side is a long, gentle slope with a greater rise in the upper part, while the 

south side is steep and the stream flows near its base. The asymmetry of this part 

of the valley is repeated in Eureka, Pioneer, Hutlina, Omega, New York, California, 

and many other creeks of the region whose valleys lie in parallel or nearly parallel 

directions.

The rocks in the upper part of the valley are mostly closely folded slates and limestones. Garnetiferous schists occur at Ruby Creek, and greenstones form the bed

FIG. 1. Diagrammatic sketch of Minook Valley.

rock of the lower valley except near the mouth, where they are partly covered by 

the Kenai rocks.

The alluvials of the valley are said to be 10 to 12 feet thick and consist of the usual 

muck (soil mixed with much vegetal matter), peaty soil, and gravel, with much 

angular debris at the foot of many of the hillsides. In the middle part of the valley 

they consist of about 5 to 6 feet of muck and the same thickness of gravel. The 

muck thickens toward the sides while the bed rock remains about level. The gravel 

deposits are derived from local bed rock and contain large numbers of smoothly 

rounded quartzite bowlders from a few inches to 3 feet in diameter, whose source has 

been a mystery to many. Some of these bowlders have undoubtedly descended to 

the present creek bed from the high benches already referred to, in whose gravels 

they are abundant.

The outcrop of quartzite near the " 72 road house " would in itself seem sufficient 

explanation for the bowlders below, but above this point the thinner quartzite beds 

have added many more to the stream. The quartzites are so hard and their abrasion 

is so slow that while the other rocks wrear into sand and small pebbles, or decompose 

and are swept away, the quartzite bowlders remain and make up a continually 

larger proportion of the gravels.

Mining. Minook Creek has not produced a large amount of gold. The wide 

valley, large stream, and heavy gravels have made mining difficult, so that men
30 GOLD PLACEES OF RAMPART REGION.

with the limited means of the ordinary prospector have found it more advantageous 

to work the smaller streams. The total production to 1904 is placed by miners of 

the region at $9,900. The gold produced is said to have been taken from the central 

portion of the valley, partly from bar diggings and partly by drifting, but in general 

the gravels do not seem to be rich enough for working by pick and shovel methods.

Nothing was learned of the occurrence of gold in the gravels of Minook Creek 

above.the mouth of Slate Creek, except that colors-have been found throughout its 

length. Below the mouth of Ruby Creek colors of gold are said to have been found 

in the gravels of a bench on the west side of Minook Creek, a few feet above the 

present stream, but not in paying quantity. The debris here is largely a graphitic 

slate somewhat schistose and highly impregnated with pyrites. An assay « of some 

of the material gave a trace of silver.

Two small areas worked in the gravels between Ruby and Slate Creeks are said to 

have given values of about $3 per square yard of bed rock; another small area is 

said to have given $4 per square yard, and nuggets of values up to $90 are 

reported to have been found. The gold is stated to be practically all upon bed rock. 

The width of the gravel in which gold is found is not known, but it is supposed to 

occur throughout the gravels which floor the valley for a width of half a mile.

A company has been formed to hydraulic this portion of the creek; considerable

preliminary Avork has been-done, some pipe, lumber, etc., were on the ground

. September 20, 1904, and a large amount of pipe and other supplies for the company

were brought to Rampart by the steamer Susie on her last trip up the Yukon for the

season.

Several schemes were on foot for working the gravels in the lower part of the 

valley near the mouth of Hoosier Creek. One proposition was to work them with a 

dredger, and another with power scrapers. Little was learned of either plan, but 

from the roughness of the bed rock dredging would seem a difficult undertaking, 

except in the limited area in which the bed rock seems to be the Kenai sediments.

HIGH BENCH.

The high bench mentioned on the east side of Minook Creek, the most prominent 

feature of Minook Valley, needs to be treated here, as on its gravels depends probably in large measure the richness of most of the placers of the Minook region.

This bench, starting at a point about a mile above the mouth of Ruby Creek and 

about 9 miles in a straight line above the mouth of Minook Creek, continues to 

Hunter Creek within about 3 miles of the Yukon (PI. IV, -A). The eastern line 

bounding the bench runs about N. 60° E.,- so that between Hunter Creek and Little 

Minook Creek the bench has a width of between 2} and 3 miles. At its extreme 

eastern, side the bench has a height of about 800 feet above Minook Creek, and it 

slopes toward the west until the height above the stream is only about 500 feet. The 

surface of the bench is remarkably smooth and continuous between the various 

streams that have cut across it, and resembles a plain through which deep ditches 

have been.cut. It seems to narrow somewhat and crosses Plunter Creek at the 

mouth of "47 Pup" continuing in a northeast direction to ward the Yukon. Although 

the writer /was unable to : follow the bench farther than Hunter Creek, miners 

assured him that they were able to trace it beyond in a northeast direction by 

gravels on the surface. 

The gravels contain chert, diabasic and metamorphic rocks, vein quartz, and some 

other pebbles with many heavy quartzite bowlders (PI. IV, B). They are exposed 

on the sides of the valleys of the different creeks cutting the bench and have rolled 

down into the present stream beds where the great number of large quartzite bowl- 

.ders make considerable trouble for the miner.

aBurlingarne, E. E., & Co., Denver, Colo.
U. S. GEOLOGICAL SURVEY IULLETIN NO. 280 PL. IV

VIE/,' WESTWARD FROM IDAHO BAR DOWN LITTLE MINOOK CREEK. 

Showing portion of high bench and intermediate bench.

B. GRAVEL OF HIGH BENCH OF MINOOK CREEK EXPOSED IN TUNNEL ON

IDAHO BAR.
MINOOK CREEK GROUP. 31

The origin of these gravels has been puzzling to the miners and prospectors. 

Their great width and depth, their position so far above the present gravels of 

Minook Creek, and the presence of the great quantity of heavy quartzite bowlders, 

Avhere the bed rock would afford no such material, have made it seem to many 

miners necessary to assume that some larger stream, possibly the Yukon itself, once 

flowed across the country. This view received some support from the apparent 

course of an old channel ether toward or from the northeast, while the present 

stream flows somewhat west of north from the mouth of Hunter Creek.

The data at hand suggest that Minook Creek while flowing toward the Yukon to 

the northeast of. its present course, when the land stood at a lower altitude, had 

formed a flood plain of approximately the dimensions of the present high bench. 

With the elevation of the land along the Yukon, the effects of which are to be seen 

over hundreds of miles, the mouth of Minook Creek may have been raised through 

local variations, -its grade may have been lessened, and the former flood plain may 

have had the gravels under discussion deposited over it. As the elevation went on, 

the creek was forced to the west and finally found a new outlet to the Yukon. The 

elevation continued, and Minook Creek cut downward, leaving its gravels on a bench 

above it. The elevation did not, perhaps, proceed steadily but periodically, and 

thus intermediate benches Avere formed.

The smaller creeks, Hunter, Little Minook, and Hoosier, all give some support to 

this hypothesis. By reference to the map (PI. Ill, p. 26) it will be noticed that 

each of them, upon reaching the edge of the bench gravels, sharply changes its 

course and flows westward through the high bench. In the case of Hunter Creek 

and Little Minook Creek the change in direction amounts to about a right angle, 

while with Hoosier Creek the angle is less acute but still noticeable. The eastern 

limit of the bench, gravels probably marks the mouths of the various streams when 

this line represented the course of Minook Creek. As the course of Minook Creek 

was shifted to the west the tributary creeks followed under the influence of the 

same force that shifted the larger stream. The age of the bench is probably Pleistocene, as is shown by vertebrate fossils found in the gravels of Little Minook 

Junior Creek, which seem to be the oldest gravels of the streams cutting the bench.

 Gold has been found in the bench at many places, and between Little Minook 

Creek and Hunter Creek a large amount of prospecting has been done. This portion of the bench is known as "Idaho Bar." One shaft near the middle of the divide 

toward their eastern edge is said to have shown the gravels to .be over 100 feet thick. 

Many other prospect holes have been sunk in them at various places, and tunnels 

were run above Little Minook Creek at their eastern edge. Three claims upon.this 

portion of the bench have been patented. From the bottom of one prospect hole, 

between Little Minook Junior Creek and Hoosier Creek, $27 was reported to have 

been taken, but drifting failed to show pay. Above Florida Creek, in the small area 

of high gravels known as "Macdonald Bar," prospect holes gave colors but no pay 

Apparently the gravels of the bench are nowhere rich enough to pay for drifting, 

although if it were possible to get hydraulic water to them cheaply they might, perhaps, be worked at a profit. The aneroid barometer readings, though not very reliable, suggest the possibility of bringing water from a point 3 or 4 miles above the 

mouth of Granite Creek under sufficient head to work at least a part of these 

gravels, if prospecting should show them to be rich enough to warrant the expense.

CHEEKS CTJT'.I.TN'G THE HIGH BENCH.

Hunter, Little Minook, Little Minook Junior, Hoosier, and Florida creeks cut 

tlirough the high bench just described. Of these, Little Minook Junior and Florida 

creeks have their channels in large part or wholly within this area, while, as already . 

noted, the other creeks lie partly outside and change their courses noticeably upon 

reaching it. The three longer creeks head close together in the hills which extend
32 GOLD PLAOEES OF EAMPAET EEGION.

northward from Wolverine Mountain and divide the Minook drainage from that of. 

Troublesome Creek. Their valleys, even at the heads, are so steep that the trails 

leading out of them are exceedingly difficult to travel.

Hunter and Hoosier creeks not only have had a sufficiently large flow to cut their 

canyons, but they did it quickly enough to have since had opportunity to widen 

them, while Little Minook Creek with its smaller volume has not yet graded its 

valley sufficiently to do so much side cutting, and Little Minook Junior and Florida 

creeks lack much of having cut their beds down to grade.

HUNTER CREEK.

General description. Hunter Creek is the first tributary of any size above the 

mouth of Minook Creek. . It is between 12 and 15 miles long, carries probably a 

little over 40 second-feet, and flows in a steeply walled canyon-like valley through 

its whole length. In its upper 7 or 8 miles it flows almost north until it comes to 

the line of the high bench, when it turns at a right angle and flows west to Minook 

Creek.

Through the upper part of its course it is a crooked stream with a narrow V-shaped 

valley, probably indicating a rejuvenated drainage, while at its turn into the high 

bench the course becomes almost straight, showing a young, rapidly cut valley. 

It has but one tributary below the bend Dawson Creek entering from the south 

about 4 miles above the Minook. In the lower part of the valley of Hunter Creek 

the two sides are unlike. On the south side the upper 300 or 400 feet of the valley 

wall is very steep, almost precipitous. The descent then becomes gentler and forms 

a broad bench which slopes easily to the creek where it ends abruptly with a face 

15 to 40 feet high. This bench is probably to be correlated with the lowest one on 

Minook Creek. It is covered with gravel, varying in thickness from 5 or 6 feet to 

15 feet, and with muck varying in thickness from 1 foot near the creek to 40 feet or 

more near the hillside.

The creek flows tortuously through its bench, retaining the meanders it had before 

the bench was formed, and generally is close to the north' side of the valley, but 

occasionally, as about 4 miles above the mouth, it wanders toward the south side, 

cutting away most of the bench. The valley has a grade in its lower part of 75 to 

80 feet per mile.

Gold was discovered in Hunter Creek Valley by William Hunter (for whom the 

creek is named) in 1896, at a point about 1£ miles above the mouth. Few definite data were obtainable concerning the gold production of the creek, but it is 

believed to have been approximately $24,000, of which $3,000 was produced during 

the winter of 1903-4 and $3,000 during the summer of 1904, a total for the year of 

$6,000. Hunter Creek has so far not proved to be a rich creek, though gold has 

been found in the gravels of both the bench and the present stream bed.

At the head of the creek the bed rock is mostly Kampart slate and quartzite; 

tuffaceous greenstones which predominate in the lower part of the valley are overlain near the mouth by Kenai sandstones and conglomerates. The tuffs contain 

some rounded pebbles, and a hole 228 feet deep was sunk in them under the 

impression that they belonged to the frozen muck and gravels of the creek. The 

rocks are much jointed and contain many small veins of quartz and calcite. Pyrite 

occurs at many places.

The gravels of the creek are 2 to 12 feet thick and are mostly diabase, slate, and 

chert pebbles from the bed rock, with many heavy bowlders of quartzite, occasionally reaching 3 feet in diameter. These larger bowlders are residuals from the 

gravels of the old bench through which the valley is cut. Much of the diabase 

gravel is angular or subangular. The muck over the gravel varies in thickness from 

1 foot in places along the stream to 40 feet or more where the small streams pour 

their debris upon the valley floor.
U. S. GEOLOGICAL SURVEY :ULLETIN NO. 280 PL. V

A. AUTOMATIC DUMP GATE DISCHARGING, CLAIM NO. 3 BELOW, LITTLE 

MINOOK CREEK.

B. HYDRAULICK1NG ON HUNTER CREEK ABOUT 4 MILES ABOVE THE MOUTH,

The ground ice is shown by the darker places in the bank on the left. The bowlders have come from 

trie high bench of Minook Creek, through which Hunter Creek cuts.
MINOOK CREEK GEOUP. 33

Mining. During the summer of 1904 work was being done on Discovery claim, 

about 1£ miles above the mouth of the creek; and on No. 17, a claim about 4 miles 

above the mouth. Several claims between these were being prospected.

On Discovery claim a flume 2,000 feet long, 30 inches wide, and 20 inches deep 

carried water to a bench about 16 feet above the' creek. The bench was covered by 

5 to 6 feet of gravel and over this was 1 to 4 feet of muck. The muck and gravel 

were practically all sluiced off, and the loose bed rock in wiiich the gold is found to 

.a depth of about 18 inches, was shoveled into sluice boxes. The bed rock is partly 

a diabase and partly a much-folded brown, cherty shale standing on edge. The 

large bowlders were moved by hand. Three men ground-sluiced an area 75 by 150 

feet in thirty days. The gold is mostly bright, smooth "pumpkin seed," with a few 

small rough pieces (PI. VI.) A considerable amount of small barite pebbles and 

some hematite occur in the concentrates.

On claini No. 17-A a hydraulic plant was installed during' the season of 1904. 

About a mile of combined ditch and flume had been put in, about 3,000 feet of which 

Avas flume, 32 by 1.8 inches, delivering 300 inches of water under a head of about 75 

feet. A No. 1 Hendy Giant with a 3-inch nozzle was being used (PI. V, B).

In working the ground the niggerheads and moss are torn up with a team and 

harrow and washed off with the nozzle. The ground is then left for a week, during 

which time the muck will thaw 1 to 2 feet. This is then washed off. The process 

is repeated until the top is removed. The remaining gravel thaws much more rapidly than the muck. It is found that the gravel can thus be thawed and made ready 

for sluicing much faster than a hydraulic giant working steadily can wash the gravel 

into the sluice boxes. In one instance an area 125 by 250 feet was worked out in 

40 days. The gravels are 2 to 12 feet thick, averaging about 6 feet, and are covered 

by 1 to 40 feet of muck. The maximum thickness was found at the mouth of a small 

tributary gulch where the gravel is mixed with angular fragments of rock. The 

muck contains much ground ice, which thaws readily when hydraulicked. The ice 

occurs occasionally as "dikes." One such was encountered over 400 feet long and 2 

feet thick, intersecting the surface layer of muck and a flat lenticular mass of ground 

ice down to the gravel, making a depth of 12 to 15 feet.

The gold is found through the lower 3 feet of gravel and in the rough broken bed 

Vock, which is made up of diabase and thin-bedded quartzite. It is bright and 

smooth, and nuggets up to 10 ounces in weight have been found. There is a small 

amount of rougher gold. Colors of gold are said to occur throughout the length of 

the creek, but no workable deposits have been found above the eastern limit of old 

gravels on the high bench already described. The larger part of the gold has probably been reconcentrated from this bench. The smaller portion of rough gold has 

probably a local source in the rocks of the creek valley. Drifting is done in the 

winter at a number of places on the creek, but little information could be obtained as 

to results.

LITTLE MINOOK CHEEK.

General description. Little Minook Creek empties into Minook Creek about 5 miles 

from the Yukon and about 1£ miles above the mouth of Hunter Creek, and has so far 

been the largest producer of the region. In drier years it carries scarcely a sluice head 

of water. It has a grade of 100 feet or less per mile in the lower 3-mile section to which 

all the mining has been confined, and its course is remarkable in being nearly parallel to Hunter Creek, though considerably shorter, as it has a length of only about 8 

miles. Like Hunter Creek it makes a sharp bend upon entering the high bench about 

3 miles from Minook Creek. Above this bend Little Minook Creek has a maturer 

character, as shown by the more, crooked valley and greater number of tributaries, 

while in its course through the bench it has a straight sharply V-shaped valley

Bull. 280 06 3
34 GOLD PLACERS OF RAMPART REGION.

(PL IV, p. 30) cut to a depth of 500 to 700 feet, and so narrow that for over three 

months of the winter the sun can not be seen from the bottom of the valley.«

The creek follows closely the southern side of the valley through its lower 3 

miles, and mostly the western side above this. It seems likely that the greater 

accumulation of talus on the north side of the creek is due to the greater amount of 

sunshine it receives, resulting in a greater amount of breaking down of bed rock by 

alternate freezing and thawing.

Gold was first discovered upon the creek in the early nineties by John Minook, 

who is reported to have taken out some gold near the mouth of the creek. The first 

claim, however, was locate'd and worked by Mr. F. S. Langford in 1896, since which 

time the'Creek has been worked continuously. The total production of the creek is 

calculated, from the best a'seer tain able figures, to be $486,100, of which $40,000 was 

taken out during the winter of 1903-4 and $2,900 during the summer of 1904, making 

the output for the season of 1904 $42,900. . Little Minook Creek heads among slates and quartzites cut by small decomposed! 

acid dikes. A little over a mile below the head, the creek is crossed by a belt o£ 

clayey, nonfossiliferous limestone, accompanied, as is often the case with the Earnpart rocks, by green fine-grained slates. Below this there is aivindistinct series of 

interbedded quartzites, cherts, siliceous shales, and some sandstones, all greatly contorted and accompanied by large masses of greenstones which form probably the 

larger part of the bed rock of the lower valley. At the foot of the valley walls the 

exposure of igneous rocks seems to be greater than in their upper parts; that is, 

erosion seems to have exposed larger masses of igneous rocks. Small veins of quartz 

and calcite occur in the rocks, but none .of great extent. The rocks of the valley 

have a considerable impregnation of iron pyrites, the oxidation of which has stained 

them the familiar rusty brown of iron oxide.

The placer deposits are all in the stream bed. The valley has been cut down so 

quickly that no bench deposits have formed. The alluvial deposits .of Little Minook 

Creek vary in thickness from 7 to 25 feet, of which gravel forms 3 to 12 feet, and 

muck, though occasionally absent, generally 3 to -16 feet. The deposits are shallowest in the lower part of the creek. The gravels contain fragments of many rocks,, 

of which diabase is probably most abundant, but slate, grit, and niuch vein quartz 

also occur, and there are many large quartzite bowlders from the bench above. 

Much of the gravel, as would be expected in a weak stream, is subangular.

In the gravels mammalian bones are said to be found, although none were seen.by 

the writer. In places clear ice is uncovered in digging, the structure of the alluvium 

showing how sudden floods had drifted detritus over the ice in the spring, and had 

thus preserved it. Locally there is much wood in the muck.

Occurrence and character of the gold. Values are found in the lower part of the 

gravels through a thickness of 1 to 3 feet, and a width of 50 to 200 feet. The gold 

frequently occurs in the bed rock, particularly the broken diabase, to a depth of 1 

to 2 feet. The pay streaks extend up the creek only as far as the creek has cut 

through the high bench gravels, a distance of about 3 miles. There are sixteen 

1,000-foot claims within these limits.

The creek has been well prospected throughout its length, and although colors 

are found there is no pay above the line of the high bench. A small amount of 

gold, in which were some large nuggets, has been found in the gulches leading from 

the high bench. The amount of gold carried by the gravels varies greatly, but in. 

the pay streak probably runs from $2 to $10 per square yard. The gold is generally 

smooth, chunky, and bright (PL VI, j, k, 1, p. 38), and shows a large'amount of 

wear. In the upper part many nuggets are found weighing 1 to 12 ounces apiece, 

but the gold gets finer downstream until near the mouth it is nearly all flat, smooth,

a Peck, C. W., and Laboskie, Wallie, personal communication.
MINOOK CREEK GEOUP. » 35

bright, and even in size, looking like golden bran when seen in quantity. There is 

a very small amount of rough gold, probably of local origin, but the larger partis 

probably reconcentrated from the old bench gravels of Minook Creek. The gold of 

the creeks cutting this bench is said to assay over $19 per ounce. This would make 

it of about the same value per ounce as the Koyukuk gold. The gold is taken in 

trade by the stores at $18 per ounce. Some small nuggets of copper and a small 

amount of silver have been found with the gold.

Mining. Most of the claims are worked by drifting in the winter, though the three 

lower ones are worked during the summer by open cuts. On the latter the muck 

and gravel are first ground-sluiced off within 1 or 2 feet of bed rock by means of a 

dam and automatic gate (PI. V, A, p."32), and the remaining gravels are then 

shoveled into the sluice boxes. The drifted pay gravels have often been "coyoted" 

or "gophered;" that is, holes have been sunk here and there without system until, 

although there is probably much pay still left, the ground is frequently almost 

unworkable on account of the ice in the old holes which floods the new workings 

when thawed by a steam point. When workings are filled with water, the mass is 

said to freeze on the top, sides, and bottom, while the central part remains unfrozen 

through several years. Much of the ground is worked on "lays" or leases, the 

lessees paying from 25 to 55 per cent of the gross output,-an amount that is apt to 

leave the worker little for his labor if things do not run very smoothly. Freight 

rates are 2 cents per pound in winter and 4 cents per pound in summer.

The remaining gold in Little Minook Creek would seem to be best recovered by 

working the claims in cooperation as one company, for it is certain that some of the 

richer claims can no longer be profitably worked by drifting. The quickest, but an 

initially expensive, mode of working would be to hydraulic the gravels by bringing 

water from Minook Creek. A ditch 10 miles in length above the mouth of Little 

Minook Creek would probably give a head of over 100 feet and plenty of water at the 

upper limit of the pay gravels. A way requiring less capital, but much slower, and 

the one that will likely be carried out in the end, is the ground-sluicing of the claims, 

successively, from the mouth of the creek upward, by means of dams and automatic 

gates, but as the claims belong to different parties, some of whom are unwilling to 

sell, there will probably be only a small amount of work carried on along the creek 

for a number of years to come. '

LITTLE MINOOK JUNIOR CKEKK.

General description. Little Minook Junior Creek, between Little Minook and 

Hoosier creeks, is about 2£ miles long. Its valley lies wholly within the high bench 

of Minook Creek. It is a weak stream, generally dry during the summer, and rarely 

carries a sluice head of water. AVith a valley of hard rocks it has not been able to 

cut its bed down to the depth reached by the larger tributaries of Minook Creek. 

In the lower half the grade of the creek is torrential and the valley is narrow with 

steep sides. In the upper half the grade is much easier and the valley is wider with 

gentler slopes, especially on the north side. The rocks of the valley are the same as 

along Little Minook Creek. "The lower part is entirely in diabase.

The total output of the creek was estimated by Mr. Donald McLean at about 

$150,000, and the output for the year 1904 at about $17,000. ' .

The steep grade of the lower part of the creek has allowed little accumulation of' 

alluvium, but in the upper part the deposits have reached a'depth of 12 to 30 feet, of 

which gravel forms the lower 4 or 6 feet. The gravels are angular and largely composed of diabase with well-washed quartzite bowlders from the bench gravels through 

which the stream has cut.

In the gravels are many bones of bison, musk ox, mammoth, and horse. A very 

fine specimen of the skull of Bison atteni, with the shell still upon the horns, Avas 

taken out of Mr. Donald McLean's claim, No. 25, near the head of the creek, by Mr.
36 GOLD PLACEES OF RAMPART REGION.

McLean and Mr. Thos. Evans. This is the only specimen of this species that has 

been reported from Alaska. It was carefully removed and is now in the National 

Museum at Washington. Some teeth obtained by Mr. C. W. Peck from gravel next 

to bed rock on the same claim and referred to Dr. T. W. Stanton for identification 

were called by him " horse teeth of Pleistocene or more recent age."

Mining. There are twenty-nine 500-foot claims upon the creek, numbered from 

the mouth upward, the upper 9 or 10 of which are said to have pawl wages or more 

upon working. The pay streak is 30 to 60 feet wide and 1 to 6 feet thick, averaging 

probably 3 feet, but gold is sometimes found through the whole thickness of the 

gravel. The gravels were reported to carry $10 per square yard on one claim, which 

is probably the highest value on the creek, the values on other claims running down 

to amounts too small to pay for working.

The gold is similar to that of Little Minook Creek, mostly smooth and bright 

with a little that is rough. It is generally coarse and chunky, nuggets sometimes 

reaching 3 ounces in weight. The larger part of the gold is undoubtedly reconcentrated from the high bench of Minook Creek. The small amount of rough gold has 

probably had its origin in the bed rock.

The gravels have been mined by drifting with steam points, but advantage was 

taken of the wet season of 1904 and some ground sluicing was done in gravel and 

muck 16 feet thick. Trees and brush in the lower part of the creek were cleared 

away in preparation for further ground sluicing. The cost of mining by drifting is 

50 per cent or more of the output, but as there is so little water it has been the only 

feasible mode of work. The creek is considered to be nearly worked out.

HOOSIER CKBBK.

Hoosier Creek flows into Minook Creek from the east side between 5 and 6 miles 

from the Yukon. It is a stream of about the same volume as Hunter Creek and has 

a valley of about the same gradient and general section, but it shows no sign of the 

bench that appears along Hunter Creek. Like Hunter and Little Minook creeks, its 

course bends to the left upon entering the area of the high bench of Minook Creek, 

although in a less degree.

The production of Hoosier Creek is unknown. There is assigned to it but $500 in 

the table (p. 169), $227 of which was in one nugget. Other small amounts have 

been taken out, but the production has not been large, and it has been almost 

impossible to thoroughly prospect the creek on account of live water in the gravels.

The bed rock is similar to that of the other creeks cutting the bench. Quartz veins 

up to 18 inches in width occur rin the diabase, and there is some pyrite distributed 

through the rocks. The alluvial deposits vary in thickness from 6 to 15 feet, of 

which 1 to 9 feet is gravel, averaging probably about 6 feet, and 1 to 10 feet is muck, 

averaging perhaps 6 or 7 feet. There is thought to be a pay streak about 100 feet 

wide whose length coincides with the distance the creek flows through the high 

bench, but the gravels of the valley are broader than those of the other creeks 

described, and with the live water the pay is hard to locate^.

Two miles above the mouth of the creek a hydraulic plant has been installed and 

had just gotten in shape to begin work at the end of the season of 1904. A combined 

ditch and flume 4,300 feet in length delivered 500 miner's inches of water under a 

head of about 80 feet. A hydraulic elevator is used to dispose of the tailings.

FLORIDA CREEK.

Florida Creek is only about 2 miles long, lying in the high bench of Minook Creek 

about 2 miles south of Hoosier Creek. Ordinarily it is dry during the summer and 

fall. The gradient of the stream is high and the valley narrow. The bed rock is 

almost entirely of diabase. The alluvial deposits are narrow, but in places reach a
MINOOK CREEK GROUP. " 37

depth of 15 or 20 feet. Nuggets up to $33 in value have been taken from the creek, 

but so far as known not more than a total of $2,000 has been obtained, though the 

stream has been.well prospected. The first prospect showed up so well that miners 

at once located the whole of the creek, and a number of good cabins were erected on 

the different claims. Some ground sluicing was done on the lower part of the creek 

during the season of 1904, but no other work was done.

ORIGIN OF THE GOLD.

The great difference in the richness of the several creeks flowing through the high 

bench of Minook Creek, and the variation in the richness of claims and size of nuggets on the same creek within the limits of the bench, show that the gold is not 

evenly distributed through the gravels of the bench. Thus Hunter Creek has so far 

shown no rich claims, while Little Minook Creek has been very rich in places, and 

along the latter the gold is very coarse on the upper claims but grows much finer 

toward the mouth (PI. VI, j, k, 1, p. 38), showing that probably the larger part of 

the gold in the lower portions of the stream has been washed down from the upper 

claims. The gold in the bench gravels was probably concentrated from local goldbearing zones in the rocks worn away above the level of the high bench. How 

great a thickness of these rocks was disintegrated and carried away can not be told, 

but there may have been many hundred feet. The rocks were probably the same 

as those now forming the bed rock. The gold in the bench gravels is said to be well 

worn, but gold found in the gravels of a stream as large as Minook Creek is generally well worn, and in this case we have no clue as to the length of time through 

which wearing may have continued. >

OTHER TRIBUTARIES OP MISTOOK CREEK.

RUBY CREEK.

Ruby Creek flows into Minook from the west side about 9 miles from the Yukon. 

It is a stream carrying 300 to 500 miner's inches (7.5 to 12.5 second-feet) of water, 

with a grade of about 150 feet per mile in the lower part. In this part the valley is 

broadly V-shaped, with steeply sloping sides. The upper part was not seen.

The first pay was taken out of the creek in 1901, and the total product is said to 

have been $13,000 or $14,000, although this estimate may be a little high. About' 

$5,000 was reported during 1904. No pay has been found above 1$ miles from the 

mouth of the creek, but it is claimed that no holes have been sunk to bed rock on 

account of the live water in the gravel.

The bed rock is the calcareous schist, garnetiferous mica-schist, carbonaceous slate, 

chert, and grit, intruded by greenstones (diabase?). The bedded rocks strike almost 

north and south across the creek with the dip downstream (east). The alluvial 

deposits are 6 to 10 feet thick and 300 to 500 feet wide. In some places there is almost 

no muck and nowhere is its depth more than about 4 feet. The gravels are 5 to 7 

feet in thickness and the total thickness of rnuck and gravel is 6 to 10 feet, averaging 

nearer the lower figure. No large chert or quartzite bowlders are seen as in the creeks 

cutting the high bench. There are some gneiss pebbles, which indicate the probable 

presence of gneiss on the creek. The gravel is comparatively fine but contains .a few 

bowlders a foot or more in diameter.

The gold is all on bed rock and is distributed through the whole width of the 

gravels. The only gold seen came from a point about one-half mile above Minook 

Creek. It was somewhat iron stained and in general rougher than the gold of the 

creeks cutting the high bench. The larger pieces were very smooth, but the smaller 

pieces were rough and most of the gold is rather flat. The gold is said to be rougher 

in the claims below. Nuggets up to about 2 ounces in weight are obtained. In the 

concentrates with the gold are large quantities of garnets that sometimes reach 1 inch
38 " GOLD PLACERS OF EAMPAET REGION.

in diameter. A handful of garnets was obtained from a pan of dirt. There are so 

many of them that they give considerable trouble by filling up the spaces in the 

riffles and must be cleaned out once or twice a day. Some barite is said to be present, 

and an occasional silver nugget appears, one weighing 2 ounces having been reported. 

The silver nuggets are very rough.

It seems likely that the origin of the gold is in the local bed rock, which along 

this part of the creek is a carbonaceous slate of irregular cleavage. In places much 

pyrite is distributed through it. The creek has been worked during the summer by 

open cuts and in the winter by drifting, but it has probably paid little, if anything, 

more than wages. Preparations were being made to install a hydraulic plant, and a 

mile of steel pipe, consisting of 720 feet each of 20; 19, 18, 17, 16, 15, and 14 inch 

pipe with branches of 11-inch pipe for an elevator, and 7-inch pipe for a giant, was to 

be put in. It was said that it would deliver the water under a head of 154 feet.

SLATE CREEK.

Slate Creek, a western tributary of Minook Creek, about 12 miles from Yukon Eiver, 

is about 4 miles long and is said to always carry at least a sluice head of water. It 

has a grade in the lower portion of about 150 feet to the mile, and the valley is narrowly V-shaped.

The creek has been worked only since 1902. Freights from Rampart are 8 cents 

per pound in summer and 4 cents per pound in winter.

The bed rock in the lower part is much-folded shaly limestone, green and purple 

slates, and cherty beds, with a northeast strike. The main rock of the valley is a 

dark graphitic schistose slate which breaks into pencil-like fragments and contains 

many quartz seams. Most of the work has been clone nearly 2 miles above the 

mouth by drifting in the winter. The deposits here are 26 feet thick.

Gold is found in as much as 3 feet of gravel and to a depth of 1£ feet in bed rock 

and over a width of 50 feet. An $8 piece is the doarsest thus far taken out. Silver 

is a common associate (PI. VI, b), and an 8-ounce nugget has been found. Copper also is said to occur in the gravels. The absence of garnets indicates that 

the schists of Ruby Creek do not extend into, the valley. The gold in this case has 

probably been derived from the small stringers common in the bed rock.

THE BAKER CREEK GROUP. 

GEISTERAL, DESCRIPTION.

The Baker Creek diggings are situated from 28 to 32 miles by trail almost south 

from Rampart, and occupy a narrow belt with a northeast-southwest extension of 

about 9 miles. Along Baker Creek itself there have been no placers discovered so. 

far, all at present known being on the tributaries flowing from the divide separating 

the Minook and Troublesome drainages from that of Baker Creek. The principal 

diggings are located along Pioneer, Eureka, Glenn, Gold Run, Omega, and Thanksgiving creeks.

The topography is strikingly different from that, of the other two areas. Baker 

Creek flows along the southwestern side of a large flat, 7 to 9 miles broad in its 

widest part, and perhaps 10 miles long, its longer extension being northeast-southwest 

in" the line of flow of Eureka and Hutlina creeks. Instead of sharp canyon-like 

valleys the streams flow through open valleys, and where they flow in general 

parallel to the Baker-Minook divide that is, approaching a northeast-southwest or 

an east-west direction, the southern bank is steep while the northern one is gently 

sloping, the creeks flowing close to the steeper side. Even along the broad Baker 

Flats this feature is still prominent. The north side is a long gentle slope toward 

the divide, rising more sharply in its upper part, while across the flats the southern 

side may be seen rising abruptly from the valley floor.
BULLETIN NO. 2BO PL. VI

 a

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jk ;£'*>.$

** »

4

' *

*

GOLD SPECIMENS.

rt. Gold from Discovery claim, Hunter Creek. (/. Gold from Seattle bar. 

'

. . 

b. . Native silver from Claim No. 10 above, Slate Creek. '/;. Gold from Discovery claim, Doric Creek.

C. Gold from Shirley bar.

d. Gold from Claim No. 1 above, Thanksgiving Creek. 

e. Gold from Claim No. 3 above, Thanksgiving Creek. 

/. Gold from Claim No. 1 1 above, Omega Creek.

. , 

/. Gold from What Cheer bar..

j. Gold from Claim No. 8 above, Little Mmook Creek. 

A1 . Gold from Claim No. 3 belo

/. . Gold from Claim No. 4 below

All the specimens are natural size.

Little Minook Creek 

Little Minook Creek'.
BAKER CREEK GROUP. 39

The main streams of the Baker Creek gold area are: Eureka Creek, lying next to 

the Baker-Minook divide, flowing southwesterly for about 5 miles, then turning to 

the south; Pioneer Creek, flowing parallel to Eureka between 1 and 2 miles to the 

southeast and joining it on Baker Flats; Rhode Island Creek, flowing in a southerly 

direction, about l£ miles west of Eureka Creek; and Omega Creek, in the western 

part of the gold area. Into these creeks flow all of the smaller creeks of the area 

along the Baker-Minook divide. The streams are all small, many of the smaller 

ones being ordinarily dry during the summer and fall. The gradient of the larger 

streams is comparatively low and it re with difficulty that water is carried to the 

benches.

The only practical trail to and from the Baker Creek area is from Rampart along 

Minook Creek, a trail that in most parts of "the States".would be considered practically impassable during the summer time. Most of the way it is soft and miry. 

The pack horses sometimes sink to their girths, floundering and wallowing their way 

through. As a choice, there is the bed of Minook Creek along which, if the creek 

is not.too high, the horses can make their way on the bars and through the icy water; 

but at best this trail is hard on the animal*. The foot traveler can not take the creek 

bed, and if he carries a pack, as he often does, he must make his way along the 

mucky trail. Over this trail all provisions for the camps are carried. Freight rates, 

until the summer of 1904, were 25 cents a pound in summer and 6 cents in winter, 

and it is said that one man had to pay freight on 47 pounds of "grub " and 53 pounds 

of box and packing at the higher rate. During the summer of 1904 freight rates 

came down to 15 cents a pound, but the packers declared they could make nothing 

at that rate, and this is'probably true, as hay and oats when cheapest are $100 a ton. 

There is another trail to the mouth of Baker Creek, but it is said to be bad and is 

not used.

Lumber is high, most of it being shipped from the States of the Pacific slope. 

Some is whip-sawed along Baker Creek in the winter, which costs about 20 cents a 

foot, board measure. It would seem that a small sawmill operated through a portion of the year would be a paying investment, as there is said to be plenty of timber 

along Baker Creek for local needs.

The total production of the region is estimated to have been about $406,100, of 

which $84,700 was produced during the winter of 1903-4 and'$61,300 during the 

summer of 1904. These figures are probably under rather than over the actual 

amount.

Gold was discovered in the Baker Creek area on Eureka Creek, where mining was 

begun during the winter of 1898-99 aiufa small amount was taken out. On Glenn 

Creek gold was discovered in July, 1901, on the benches along Pioneer Creek in 

1902, on Thanksgiving Creek in February, 1903, and other discoveries were made 

during the summer of 1904. Prospecting is in active .progress in other valleys of the 

vicinity, and it is altogether possible that new discoveries may be made.

The rocks of the Baker Creek group show less variety than those of the Minook 

Creek group. In the gokUbearing region the rocks are schistose arkoses with interbedded slates and with quart/ites, the latter in thin strata, generally 1 to 3 feet 

thick. Both slates and schistose beds are generally graphitic. The strike is northwest and the dip about vertical. No igneous rocks occur except along the top of the 

divide, where there are some dikes and masses of a rnonzonitic rock. Quart/ occurs 

generally only in small veins, and these are not prominent. In places there is a 

considerable amount of. pyrite in the rocks in small crystals'and grains, but no large 

masses or veins have been seen. ' <-
40 GOLD PLACEES OF EAMPAET EEGION.

THE CREEKS A1STD BENCHES.

EUREKA CHEEK.

General description. Eureka Creek, on which gold was first discovered in this area 

(in February, 1899), flows south westward along the foot of the Baker-Minook divide. 

It runs in a straight southwest course .for about 4£ miles, then turns and runs south 

2£ miles to its junction with Pioneer Creek. It has a number of small tributaries 

from the northwest side, but none from the southeast. The largest is Boston Creek, 

about 2 miles long,'which joins Eureka Creek at its bend. The other tributaries are 

mere rills. Eureka is a small creek carrying barely a sluice head of water above the 

mouth of Boston Creek during the ordinary seasons. From aneroid barometer readings the gradient of the stream is about 100 feet per mile. The valley slopes gently 

to the divide on the northwest side, but on the southeast side the slope is almost 

precipitous, rising 400 to 600 feet above the valley. The creek flows close to the foot 

of the steeper side.

The gravels of the creek are not much worn, as is characteristic in weak streams, 

and have been left for a considerable distance, in places at least 500 feet, up the slope 

of the hill as the stream bed has moved to the southeast. The bench gravels, like 

those of the present stream bed, are made up entirely of the country rocks. The 

deposit varies in thickness from 5'to 18 feet, and the overlying muck varies from 

nothing to 8 feet, the distribution being rather irregular. The total thickness varies 

from 5 to 20 feet. The gravel contains a considerable amount of very sticky clay, 

which makes sluicing difficult. The clay seems to come from the decomposition of 

both the arkose and the slates.

Mining. Only one claim above and one below the mouth of Boston Creek have so 

far been made to pay, but prospectors on the bench gravels about 2 miles above the 

mouth of Boston Qreek reported that they had found gold in sufficient quantities to 

pay for ground sluicing, if not for drifting. On this part of the bench it is 8 feet to 

bed rock near the creek, and 450 or 500 feet back from the stream it is 20 feet. The 

elevation above the creek at this distance, as shown by the aneroid barometer, is 

70 feet.

The gold is said to be in the lower 18 inches of gravel and in a foot of bed rock. 

Along the creek the bed rock is largely blocky, and in it gold is found to a depth of 

3 feet; but it. is not found at such depths where the bed rock decomposes into clay. 

The gold may be distributed through the gravels to a depth of 4 or 5 feet, but it is 

generally close to bed rock, which must be scraped.

The larger part of the mining has been done by drifting, but on Discovery claim, 

just below the mouth of Boston Creekr an open cut is being worked. The muck and 

upper gravel are ground sluiced through sluice boxes, so as to save any fine gold that 

may be in them, and the lower gravel is shoveled in. Fifty-seven 12-foot boxes are 

used, 37 of which contain pole riffles and 2 contain Hungarian riffles. The lower 

boxes are lined with sheet iron to facilitate the movement of the gravel. Some gold 

is probably carried off by the sticky clay in spite of the length of the sluice box.

PIONEER CREEK.

General description. Pioneer Creek heads against the Baker-Minook divide, flows 

around the head of the Eureka, and then, at a distance of 1 to 2 miles, flows parallel 

to the main course of that creek. After traversing 7 or 8 miles it joins Eureka 

Creek and they are said to lose themselves on Baker Flats. Pioneer Creek is larger 

than Eureka Creek; probably it never carries less than three or four sluice heads of 

water, and its gradient along its lower course is about 60 feet per mile. The valley 

is similar to that of Eureka Creek. Its northwest side is a gentle slope running back 

for about a mile, and the southeast side is of almost precipitous steepness, but not so 

high.
BAKEE OEEEK GROUP. 41

On the gentle slope of the northwest side there are perceptibly flatter places or 

benches, but only one of these is persistent. This bench is traceable along Pioneer 

Creek for over 4 miles. Its northeast end is but little above the present level of the 

creek while its southwest end is about 250 feet above the creek. Over this bench 

and covering, much of the slope below is a deposit of auriferous gravel left by the 

creek as it moved to the southeast. The different diggings upon it are known as 

"bars."

- Five small tributaries, Doric, Boothby, Seattle Junior, Skookum, and Joe Bush, 

flow across this bench at right angles to the course of Pioneer Creek. Near the 

upper end of the bench at Joe Bush Creek prospect holes showed a well-defined old 

stream channel. Upstream the bench rises so that a ditch supplying water to What 

Cheer Bar is below the workings at Seattle Bar, but crosses the bench and is on the 

upper side when it reaches What Cheer Bar. There can be no doubt that the bench 

is of stream origin.

Like many other Alaskan creeks Pioneer Creek was staked and then each man 

waited for his neighbor to do the hard work necessary to locate the pay streak, if 

there were one. Meanwhile the claims lapsed and were then restaked by other 

parties, and pay was discovered on What Cheer Bar in 1902. After this discovery 

pay was found on Doric Creek and at several other points along the bench.

The production of Pioneer Creek Valley to the end of the summer of 1904 was 

about435,800.

The bed rock is the same as on Eureka Creek, schistose-arkose, with interbedded 

slates and thin beds of quartzite. The arkoses sometimes become very graphitic, 

particularly on Doric Creek. The general strike of the rocks is N. 70° or 75° E., 

with a steep northerly dip. There is some quartz in small veins and stringers, and 

on Doric Creek at places there is considerable pyrite distributed through the rocks. 

The pyrite is often oxidized, so that only small holes lined with iron rust indicate 

its former presence. On Doric Creek inclusions of a carbonaceous substance the size 

of a walnut occur with small quartz seams. Little is known of the alluvial deposits 

along the creek bed. The deposits on the gentle slope already referred to are 3 to 12 

feet thick. They consist of the usual muck and gravel, and extend over 2,000 feet 

back from the creek.

What Clieer Bar. What Cheer Bar is located in the lower part of Pioneer Creek 

Valley, about a mile from Eureka Creek, 2,000 feet from Pioneer Creek, and 250 feet 

above the latter. The season of 1903 was spent in putting in about 4 miles of ditch, 

with the necessary flumes. This ditch carries .about three sluice heads of water to the 

upper edge of the workings. The ground is excellent for ditching, compared with 

other Alaska localities, for there is little ground ice and the soil is tenacious enough 

to make good banks. The bed rock is much jointed and broken and exhibits fine 

examples of creep, the rock leaning downhill and gradually blending with the gravels.

The average depth to bed rock is about 12 feet. The overlying material is composed of 1 to 1J feet of muck, 3 feet of rather fine flat wash, 5 feet of medium-sized 

yellowish gravel, and 3 to 4 feet of rather heavy wash, including some bowlders of 

vein quartz 2 feet or more in diameter. There are some bowlders of conglomerate 

similar to that found in Quail Creek, in Troublesome Valley, and it is probable that 

beds of it outcrop on the headwaters of Pioneer Creek. Most of the gold is found in 

the lower part of the gravels and the upper 1 or 2 feet of bed rock. It is well worn 

and bright (PI. 'VI, i, p. 38), and probably comes from the bed rock in the vicinity. 

The largest nugget found weighed somewhat less than 2 ounces and was worth $28. 

It contained considerable quartz. The gold is taken in trade at $15.50 per ounce.

The muck and upper gravel are ground sluiced and the lower gravel and upper bed 

rock shoveled in. The water could not be used until August 15, and only fifteen 

days were available for washing. Fifteen men were employed.
42 GOLD PLACEES^ OF EAMPAET REGION.

Seattle Bar. Seattle Bar is about 2$ miles farther northeast on the same bench, on 

the northeast side of Seattle Junior Creek, and about the same distance back from 

Pioneer Creek as What Cheer Bar. Pay was discovered here in the spring of 1904. 

The depth to bed rock is about 9 feet and the bed rock and gravel are similar to 

 those of What Cheer Bar. The gold occurs in the lower foot of gravel and.-the upper 

foot or more of bed rock. It is bright, chunky, and well worn. Some of it is 

rather flat, but all is easily saved. .The largest nugget obtained was worth $9.40. 

Water is obtained for sluicing by a ditch and hose from Skookum Creek, which in a 

dry year will furnish but a scant supply.

Doric Creek. Doric Creek is a small tributary of Pioneer Creek about three-fourths 

mile above What Cheer- Bar, and is dry most of the summer and fall. It has an 

open valley, at its greatest depth probably not over 50 feet below the level of the 

bench. Gold was discovered here in 1902, and in the winter of 1903-4 a portion of 

the valley about one-fourth mile from Pioneer Creek was found to be very rich. As 

with other weak streams its wash shows almost no wear, but there is also a large 

amount of more rounded gravel from the bench through which it has cut.

Only one claim has produced much gold. Some pay was found on the lower part 

of the next claim above, but none in the upper part.' The richness of the deposit is 

probably due to the reconcenfration of the gold from the gravels of the bench. The 

ground is worked by drifting during the winter, and the largest bowlders are left in 

the drifts. It is worthy of note that a large degree of the success obtained in locating this claim was attributed to the remarks upon concentration in the Survey 

report on the Nome region, « which apply with much force to many of the deposits 

of the Rampart region.

Other bench gravels. A. mantle of gravels similar to that which covers the gentle 

slope on the northwest side of Pioneer Creek bends around a spur from the divide 

on the west side of Eureka Creek and continues to Omega Creek, a distance of about 

2£ miles. Beyond this point it has .not been traced. In the space described the 

gravels are cut by Glenn Creek, Gold Run, Rhode Island Creek, and Seattle Creek.

SHIRLEY BAR.

The bench gravels have been prospected at many places and shown to carry gold, 

but at only one point outside of the creeks crossing them have they proved sufficiently rich to pay for working. This place, known as Shirley Bar, is located 

between Glenn Creek and Gold Run. It is at an elevation of about 200 feet above 

the lower workings on Glenn Creek, and was first worked in the fall of 1901. The 

bed rock is the same schistose arkose, slate, and quartzite. .The wash is small and 

subangular, with a few quartzite bowlders and some monzonitic rocks from the 

divide above. The gravel varies in thickness from 2 feet at the lower side of the 

claim to 7 or 9 feet in the middle and 5 feet at the upper end. The gold is bright, 

rounded, and "shotty," well distributed through the gravel, and, though it seems 

strange, the nuggets come from near the surface. There are few large pieces of gold, 

the largest nugget taken out weighing a little over 1|- ounces.

A ditch from Rhode Island Creek, 1 mile long and capable of carrying 2 sluice-- 

heads of water (about 100 miner's inches), has been dug; but water is so scarce that 

it is collected in a pool after being used and pumped back to the sluice boxes. For 

this purpose a 30-horsepower boiler, two twinned 4-horsepower upright engines, and 

a 4-inch centrifugal pump are used. Seven men have been employed on the claim 

during the season.

"Brooks, A.H.,and others, Reconnaissances in the Cape Nome and Norton Bay Regions, Alaska, 

in 1900; a special publication of U. S. Geol. Survey, 1901, pp. 149-151.
U. S. GEOLOGICAL SURVEY IULLETIN NO. 280 PL. VII

A. VALLEY OF G^EN,\ CREEK. 

Looking north, showing sluices, etc.

& ' -- : ''' " """ 1 .."=.'. :*!/. ?T' !VcwT : "

IS. VIEW WESTWARD UP QUAIL CREEK FROM T HE EAbT sIDE OF TROUBLESOME

CREEK.

Wolverine Mountain in the background.
BAKER CREEK GROUP. 43

GLENN CREEK.

General description. Glenn Creek is located about 1 mile west of Eureka Creek, 

and flows across the bench gravels. It is about 3 miles long, running almost south 

clown the slope from the Baker-Minook divide. The valley is shallow and open (PI. 

VII, A.), probably not over 50 feet below the bench. It is practically dry during 

ordinary summers, but during the wet summer of 1904 it carried water sufficient for 

sluicing.

Gold was discovered on Glenn Creek by Messrs. Beardsley, Belsea, and Dillon in 

July, 1901. The total production up to the fall of 1904, according to the most reliable 

information obtainable, had been about $277,500, not including the output of one 

claim known to have produced a considerable amount. During the year ending with 

the fall of 1904 $50,500 is known to have been produced, and this again does not 

include some smaller outputs. Of the 1904 output $11,000 was obtained by drifting 

during the winter of 1903-4 and $39,500 during the summer of 1904.

The bed rock is similar to that on the other creeks. The alluvial deposits are 7 to 

9 feet thick and are in large part composed of the angular fragments usually found 

in so weak a stream, with rounded material from, the bench through which it flows. 

There are occasional small bowlders of monzonitic rock from the divide above.

Thequartzite interbedded in the softer slates has given rise to a peculiar condition 

in the gravels of the lower part of the creek. On claim No. 1A a section of the 

gravels shows about a foot.of muck under which is a discontinuous layer of angular 

quartzite blocks 8 to 10 inches thick and 2 feet or more broad, showing no water 

wearing. Under these is a thickness of about 2 feet of washed gravel and fine 

broken slate lies below this upon vertical strata of slate which strike about northeast. . These angular blocks of quartzite on top of the gravel have been very puzzling. It is likely that they are to be explained by the supposition that the creep, 

which acts very strongly here, has broken down a thin bed of quartzite that can be 

seen on the side of the claim, and as the creep has moved the gravels the blocks of 

quartzite have been broken off and have crept with the gravels.

Mining. The pay seems to have been mostly, if not wholly, in that part of the 

creek which cuts the mantle of gravel"covering the hillside. The pay streak is said 

to vary in width from 50 to 100 feet. In places it was very rich; one pan taken by 

the writer gave about $3.75. Many pans of $10 and upward were said to have been 

taken. At one place fine gold could be seen all through the broken slate. On this 

claim the pay was in the lower 3 feet of gravel and 2 feet of the bed. rock. A plat 

20 by 48 feet yielded $4,000 to 4 men working three and one-half days.

The gold is bright, clean, generally worn, and fine, but "shotty" and easily saved. 

Such nuggets as ai'e found generally contain considerable quartz. The largest nugget found weighed nearly'6 ounces. It was bright, clean, beautiful gold, and showed 

the impression of large quartz crystals. It is said to assay a little over $16 per 

ounce.

A. small ditch 1 mile long brings about a sluice head of water from Rhode Island 

Creek. .Another ditch dug to bring a sluice head or more from Boston Creek was 

just ready to use when freezing began in the fall of 1904,. An average number of 24 

men are said to have been employed during the year. Some drifting is to be done 

this winter (1904-5), but it is said that most of the ground fit for drifting has been 

worked out, the remaining pay gravels being too shallow to give a good roof. The 

creek is probably more than half worked out.

GOLD KUN.

A creek, about 1£ miles long, flowing into Rhode Island Creek I mile west of 

Glenn Creek, is called Gold Run. It carries little water at any time and is practically 

dry during the sumnaer and fall. The valley is shallow and open and the lower part
44 GOLD PLACEES OF RAMPAET EEGION.

is cut through the gold-bearing gravels covering the extension of What Cheer Bar. 

The creek was staked in the spring of 1899 and the first work was done during the 

winter of 1900-1901. There are six claims, each 500 or 1,000 feet in length, upon the 

creek, but only the lower four have so far been producers. The total production 

during the winter' of 1903-4, as reported by the miners, was about $16,000, not 

including the output of one claim, which was probably small. The production of 

former years is estimated at about $9,000.

The bed rock of the lower part of the creek is a graphitic'schistose arkose, which 

in places becomes slaty. The rather well-rounded gravels are of slate, quartzite, and grit, 16 to 18 feet deep, with a covering of about 2 feet of muck. The creek 

is difficult to work on account of the live water in the gravels. Through part of 

their length the gravels are frozen on the bottom and thawed for several feet above, 

so that drifts must be timbered throughout. The pay frequently goes down into the 

bed rock 3 or 4 feet.

The 'gold is generally bright, fine, and somewhat worn. One nugget weighing 

nearly 4 ounces has been taken out. When poured out of a sack* or pan part of it 

rolls almost like shot, owing to its rounded form. This characteristic is common to 

a large part of the gold of the Earn part region, but particularly so of this area, and is 

due to its crystalline form. The crystal faces are often observable on the pieces. 

The placers of the creek are probably derived largely from reconcentration of the 

gold from the gravels of the bench through which the creek has cut its course, and 

in part from the local bed rock. The creek is probably more than half worked .out.

RHODE ISLAND CHEEK.

Rhode Island Creek is somewhat larger than Gold Run and heads nearer the top 

of the ridge. Its general conditions of bed rock, gravel, etc., are similar to those of 

Gold Run, below the mouth of which Rhode Island Creek flows close against a bluff 

on its western side, while its eastern side rises more gently.

Considerable work has been done on the creek, but during the summer of 1904 no 

claims were worked. The output is unknown. Miners on other creeks are of the 

opinion that the gravels would pay for working if water for hydraulicking could be 

obtained.

SEATTLE CREEK.

Seattle Creek, although the longer stream, is called a tributary of the Rhode 

Island. It probably carries less than a sluice head of water during an ordinary season. The bed rock in the lower part is graphitic schistose arkose. The gravels 

contain bed-rock fragments, quartzite, vein quartz, and graphitic slate, and are 

rather tine. They are said to be 8 to 30 feet thick and covered with 1 to 3 feet of 

muck. They are well frozen and have no live water. About $100 was taken out in 

the course of prospecting during the winter of 1903-4. The gold is said to be bright, 

fine, and shotty. Prospecting was to be continued during the winter of 1904-5.

' BENCH WEST OF RHODE ISLAND CREEK.

A spur on the west side of Rhode Island Creek, similar to the one on the west side 

of Eureka Creek, has a well-defined bench cut upon it, extending about one-half 

mile to Omega Creek Valley. The bench is about 300 feet above the bed of Rhode 

Island Creek and is covered with subangular gravel, through which gold is said to 

be found. It is about on a level with Shirley Bar.

OMEGA CREEK.

General description. Omega Creek, another small stream, heads in a ridge about 2 

miles southwest of the head of Minook (Jreek and about one-half mile west of Seattle

"Known among miners as a " poke."
BAKER CREEK GROUP. '45

Creek, flows almost south for one-half mile or more, and then swings gradually to 

the west. As soon as it takes a westerly course the shape of its valley becomes 

similar to that of Eureka Creek, having a steep hill on the south, against which the 

stream flows, and on the north side a gentle slope to the ridge above, rising more 

steeply in its upper portion.

Gold was discovered in Omega Creek in ]899, but the first pay was found in 1901. 

The creek has been worked in only a small way, and the production has- been 

small. The bed rock is a black, fissile, much-broken slate, and a yellowish, somewhat schistose arkose. It has a strike of N. 70° E., with a high northerly dip. The 

gravel is about 7 feet deep, very angular and fine, and is made up of the country 

rock with a small amount of quart/ite. There is little or no muck over the gravel, 

but there is a sticky clay through it which probably carries off some of the fine gold. 

Values and 'mining. The pay is known to extend for about 1 mile down the creek 

from .a point due west of the mouth of Seattle Creek. The width of the pay is 

unknown. One cut 30 feet wide has been taken out, and it is known that the pay 

extends to both sides, rising on a low bench on the right (northwest). This cut is 

at the upper end of the pay streak. The gold is distributed through the gravel 

both top and bottom. It is "shotty" and coarse, and much of it is very rough. 

Many pieces show crystal faces, and all .the larger pieces and many of the smaller 

pieces contain quart/. In color the gold is more brassy than most of the gold of 

the region. A great many small, crystals of pyrites occur in the concentrates with 

 the gold. So far the claim has been worked only by an open cut, but s"ome of the 

gravel was thought to be deep enough to be workable by drifting and this method 

was to be tried during the winter of 1904-5. The water supply is small and a dam 

has been put in to collect the water so that sluicing can be carried on about half the 

time during an ordinary season.

CHICAGO CREEK.

Chicago Creek is a small rivulet flowing down the northern slope to Omega Creek 

about 2$ miles west of the mouth of Seattle Creek. Pay was reported to have been 

discovered near its mouth during the summer of 1904, and it was the intention to 

work it during the winter.

THANKSGIVING CREEK.

Thanksgiving Creek is a small tributary of Omega Creek, between 4$ and 5 miles 

west of Eureka Creek. It occupies a shallow, open depression in the southern slope 

of the ridge, on the north side of Baker Flats, and can hardly be said to have a valley 

in its lower part. It is almost dry in the summer and fall. Gold was discovered on it 

in February, 1903. "The combined output of'Omega and Thanksgiving creeks has 

been about $18,200.

The bed rock is exposed only in the diggings, but wliere seen was a yellowish, 

somewhat'schistose arkose. The gravel varies in depth from 6 to 18 feet where the 

creek is worked, though it is said to be deeper farther downstream. It is composed 

of subangular pieces of quartzite, schistose arkose, vein quart/, slate, and a small 

amount of monzonitic rock. The overlying muck is 1 to 4 feet in thickness.

The gravel is peculiarly mixed with a sticky yellow clay, which in places seems 

to.be half ice. In some of the deeper holes there is 10 feet of this mixed clay and 

ice. It can not be worked with wood fires, for when melted it runs down upon the 

fires and quenches them. In open cuts the sides when melted move together like a 

mass of yellow tar. In some of the holes the section is said to show 10 to 12 feet of 

finely mixed yellow clay and ice, of which 5 feet is fully half ice and below this there 

is 6 feet of subangular gravel. The pay streak varies in width from 25 to 45 feet, 

and is 1$ to 9 feet thick. Gold is sometimes distributed through the yellow clay 

and color's always occur through the mixture of clay and ice. At one place where
46 GOLD PLACEES OF EAMPAET EEGION.

the pay is found through 7 feet of the ice-clay mixture, when the mass is thawed 

the pay sinks to the lower 4 feet. If the clay is dried it is difficult to part the gold 

from it, and at one claim, on which open-cut-work was progressing, .angular pieces 

of sheet iron like saw teeth were driven into the poles used in the sluice boxes to 

break up the clay. The iron pieces were left projecting about three-fourths of an 

inch, and 25 were used to a G^-foot pole. The device is said to work well.

The gold is generally rough and somewhat iron stained, but some of it is smooth, 

bright, and "snotty." Some "black sand" is said to be with it in the concentrates. 

Mr. R. H. AVright picked out 8.48 ounces of the smooth, bright gold, and the United 

States Assay Office at Seattle gave it a value of $15.64 per ounce. In it there were 

1.68 ounces of silver and 0.4 ounce of impurities; 32.03 ounces of the gold as it came 

from the sluice boxes contained 6.38 ounces of silver and 2.41 ounces of impurities, 

and had a value of $15.17 per ounce. Each assay gives about 20 per cent as the 

silver content of the gold. . Water for sluicing is brought from Eureka and Chicago creeks,.but the supply is 

. scanty. The probabilities are that the"production of gold upon Thanksgiving Creek 

will increase considerably, but as in most of the diggings of the Baker Creek group 

more water is needed.

HUTJOINA CREEK.

Hutlina Creek is a large tributary of Baker Creek, several miles southeast of, and 

having a generally parallel course to Pioneer Creek. As seen from Glemi Creek its 

valley and that of its principal tributary are shaped similarly to those of Pioneer and 

and Eureka creeks, and prospectors confirm this impression. A stampede to the 

Hutlina occurred in 1902, and it is reported, that colors and occasionally good prospects were found, but live water in the gravels prevented their being-worked without machinery. The bed rack is said to be similar to that of Pioneer Creek. At the 

time the Geological Survey party left Eampart, September 20, 1904, several prospectors were going into the valley Avith tools and provisions to prospect the benches 

during the winter.

WATER FOU HYDKATJLICKESTG.

A large part of the gravels of the creeks and benches of the Baker Creek area, 

while they will not pay for shoveling in, would probably pay for working if water 

for hydraulicking could be obtained at a reasonable cost. But, as has been said, 

the creeks of the region are small and furnish hardly enough water for. ordinary 

sluicing operations.

Miners say that Hutlina Creek would furnish plenty of water for hydraulicking, 

but the distance it would have to be carried is variously estimated at 8 to 15 miles. 

Were water brought from this creek it would have to be piped through a large part' 

of the distance to.retain the head. In connection with hydraulic mining in this 

region the writer can do no better than quote the remarks of Mr. L. M. Prindle a 

upon the subject:

Outlook for hydraulic mining. The installation of a hydraulic plant in any of the placer regions of 

the Yukon-Tanana country involves the expenditure of an amount of money several times in excess 

of that required for similar work in the States and should be preceded by much careful preliminary 

study of all the conditions. The transformation of available water supply into a powerful tool of 

excavation and transportation and the use of this tool in the most skillful and efficient manner are 

among the most important problems of mining. Lack of knowledge and skill may be covered by 

the results where the ground is very rich, but with ground like that under consideration the possession of these qualities or the lack of them may make all the difference between success and failure. 

Directors and stockholders of companies planning such work should insist upon and be constantly 

ready to bear the expense of the intelligent study of conditions and careful management of 

operations.

ciPrindle, L. M., and Hess, F. L., The Rampart placer region, in Report on progress of investigations of mineral resources of Alaska: Bull. U. S. Geol. Survey, No. 259,1905, pp. 104-119.
TROUBLESOME CEEEK GEOUP. 47

GEJSTKUAI, CONCLUSIONS.

The rocks of the Baker Creek area are interbedded schistose arkoses, slates, and 

quartzites, with the arkoses forming the larger part. The arkoses and slates are 

often graphitic. Igneous rocks were found only along the crest of the divide, and 

not in large quantity. When compared with the Klondike or the Nome goldproducing regions, the small amount of metamorphism and mineralization and the 

scarcity of quart/ veins and stringers are very noticeable.

The source of the gold is probably local, and the richer placers are generally in 

the vicinity of graphitic phases of the rocks. There is frequently reconcentration 

from older gravels where the streams cut across gravel-covered benches and hillsides. The gold, though generally close to bed rock, is sometimes distributed through 

a considerable thickness of gravel and muck. It often occurs in small cryotals, and 

is thus shotty and chunky and easy to save. Large nuggets are rare. It contains a 

large amount of silver, so .that its value per ounce is much lower than that of the 

gold of the Minook Creek area, running from $14.88 to a little over $16. There 

are few minerals accompanying the gold, a little pyrite, magnetite, and hematite 

being the only ones noticed.

The creeks are all small and some have been half worked out or more, but new 

deposits have been discovered each year and more will probably be found. Water 

for working the claims is scarce, and, although some ground which will not pay for 

shoveling in would probably pay for hydraulicking under favorable conditions, water 

in adequate quantity and under a sufficient head can not be obtained without considerable expense. One of the greatest needs is a good road from Kampart, and 

until that is made supplies must continue excessively high.

THE TROUBLESOME CREEK GROUP. 

GENEBA1; DESCRIPTION".

The Troublesome Creek group is situated between the arms of the Y formed by 

the divides separating the drainage basins of Minook, Baker, and Troublesome 

creeks. It is 18 or 20' miles southeast of Rampart. Troublesome Creek, rising 

among the hills east of Wolverine Mountain, flows northeast to Hess Creek, a tributary of the Yukon. The-tributary valleys are often narrow and shut in by hills 

with steep sides and ridges, closely resembling each other, and making traveling so 

difficult that the country has come by its name honestly.

So far pay dirt has been found upon two creeks, Quail and Gunnison, though colors 

are found through the gravels over a wide area.

The rocks include all the varieties present in the Rampart formation, but slates 

are characteristic of the upper valley and greenstones of the lower. The slates have 

been intruded by^a variety of igneous dikes. The creeks have cut benches upon 

the hills, but to a less degree than in Minook Valley.

CHEEKS PROSPECTED.

CiUAIL CHEEK.

Quail Creek heads opposite Hoosier Creek and flows eastward into Troublesome 

Creek, having a length of between 5 and 6 miles (PI. VII, .6, p. 42). A large branch 

known as South Fork joins Quail Creek about a mile above Troublesome Creek. 

Between the two branches is a gravel-covered bench 400 feet high, upon which 

colors have been found, and which is being prospected. Parts of this bench occur 

at various places farther up Quail Creek. On the north side of Quail Creek is 

another bench about 50 feet above the creek, and tins too is being prospected. In 

one hole bed rock was reached at 29 feet. There were 19 feet of muck and 10 feet 

of well-washed gravel. Colors were found all through the gravel, but no pay.
48 GOLD PLACEES OF EAMPAET EEGION.

A. number of igneous dikes which cross the lower part of Quail Creek show considerable, mineralization by metallic sulphides. An assay of a porphyry gave no 

gold, but 0.52 ounce of silver^ per ton.

The creek was located in 1898, and it is said that it was desired to call the stream 

"Ptarmigan" Creek, but as no one in the party could spell ptarmigan it was named 

"Quail," the spelling of which was easier. Some gold is said to have been taken 

out in that year, and a little was taken out during the summer of 1904. The total is 

thought to be about $3,300.

There seems to be a considerable accumulation of gravels at some places, while at 

others the bed rock rises to the surface. The gravels are of the country rock, with 

many bowlders of porphyritic granitoid rocks.

A number of miners were fixing up old cabins and building new ones, and getting 

ready to prospect the creek during the winter.

GUNNISON CREEK.

Gunnison Creek is located a few miles farther down Troublesome Creek on the 

same side as Quail Creek. Miners are said to have worked upon it during the summer of 1904, and to have taken out some gold, but no further particulars were 

learned. The creek was not visited by the Geological Survey party.

GENERAL SUMMARY.

The alluvial deposits formed from the rocks of the valleys in which the deposits 

occur are found both in stream channels and on benches, and are probably all of 

stream origin. They are of Recent and Pleistocene age, and their thickness is generally near 5 feet, but varies from 5 to 100 feet.

The gold is generally found in the lower 2 or 3 feet of the gravel and upper 1 or 2 

feet of the bed rock, but on Shirley Bar and Omega Creek it is in places distributed 

through the whole depth of the gravel, 5 to 7 feet, and on Omega Creek the gold is 

found not only in the gravel but through several feet of intimately mixed ice and 

clay.

The placers are of two general types as regards their origin, placers of ordinary 

concentration from the disintegration and wearing down of the bed rock, and placers 

formed through reconcentration of the gold in older gold-bearing gravels by the 

cutting of streams. The bench gravels of the region and the placers of Ruby and 

Slate creeks belong to the first class. To the second class belong the placers of the 

creeks cutting the high bench of Minook Creek and the placers of Doric, Glenn, and 

Seattle creeks and Gold Run. The other placers of the region probably belong to the 

first class, although there may be some reconcentrated gold in Thanksgiving and 

Quail creeks.

The gold of the reconcentrated placers is generally smoother and brighter than 

that from the others, contains less quartz and iron, owing to abrasion and oxidation, 

and is thus higher in value per ounce, though the higher value of the gold of the 

Minook group is principally due to its containing less silver than the gold of other 

creeks. There is much crystallization in the gold, particularly of the Baker Creek 

group, where the gold contains a large percentage of silver. It is notable that along 

Minook Creek, where the gold contains so little silver, native silver nuggets are found 

in the placers, while in the Baker Creek group, where the placer gold contains about 

20 per cent of combined silver, there are no silver nuggets. The only other minerals 

* known in the concentrates with the gold are hematite, a small amount of magnetite on Thanksgiving Creek, pyrite, garnets on Ruby Creek, barite on a few other 

creeks, and copper on Hunter, Little Minook, and Slate creeks.

In all cases the matrix of the gold has probably been in the immediate neighborhood of the placers, though it may be the result of the concentration of many hunaBurlingame, E. E., & Co., Denver, Colo.
GENERAL SUMMARY.

drede of feet of bed rock. There seems to be no indication that the gold has been 

derived from any great "mother lode," and it lias probably come from comparatively 

small veins distributed through the country rock,

 All of the creeks at present known to be gold bearing to a paying extent, except 

Slate and Ruby creeks, take their rise in the Minook-Baker-Troublesome divide. 

Along this divide are dikes of monxonitic, dioritic, and acid igneous rocks, and it 

may be that these were associated with causes that introduced gold-bearing solutions 

into the rocks. The large mass of diabasic rocks in the Minook group may have 

been related in some way with the mineralization of that area.

As to the origin of the silver and copper nuggets with the gold in the creeks of the 

Minook group, little can be said. On all the creeks in which they are found, except 

Slate Creek, both limestones and diabases occur. On Slate Creek diabase was not 

seen, although there is'much of it on Ruby Creek. It is likely that the silver and 

copper-nuggets come from the oxidation of contact minerals resulting from the diabasic intrusions.

The average depth of gravel worked is probably between 10 and 20 feet. The 

gravels are mostly frozen, but much trouble in working them is sometimes had on 

account of live water. Hydraulicking has been introduced and apparently works 

well in the frozen gravels.. This form of mining wi.ll probably become of considerable importance in.the Minook Creek group wherever plenty of water and head are 

obtainable. In the Baker Creek group the. expense of obtaining water for hydraulicking seems to be very much greater, though data are lacking. There is much 

gravel in this group, which can probably be worked at a profit only by this method. 

In the Troublesome country there is plenty of water, with sufficient fall for hydraur 

licking in that valley.

The following tables give the most important statistical data of the Rampart region 

and include the total gold production, so far as ascertainable, up to the fall of 1904:

Distances, men employed, and freiylit rates of Rampart region, 1904-

Name of diggings.

Slate Creek ..................................................

Gold Run ....................................................

Total ...................................................

Distance 

from 

Rampart.

Miles.

3 

4* 

5 

C 

8 

9 

11 

28 

30 

30 

30 

31 

31 

32 

34 

20

Number 

of men 

employed.

15 

30 

10

7

10

5

I "

24 

10

3 

10

5

109

Freight rates.

Winter.

Cents per 

pound.

. 2 

2 

2 

-y

3 

4

f ° 6

( c

G 

6 

6 

0 

G 

G

Summer.

Cents per 

pound.

4 

4 

4 

4

G 

8 

15 

15 

15 

15 

15 

15

15 

15 

15-20

Bull. 230 06-
50 GOLD PLACERS OF RAMPART REGION.

Gold production of Rampart region lo fall of 1904-

Name of diggings.

Total .........................................

Winter 

of 1903-4.

S3, 000

40, 000

17,000

500

3,000

12, 000

I 45,500

11, 000

16, 000

100

| 12,100

160, 200

Summer 

of 1904.

S3, 000

2,900

2,000

3,000

' 16,500

39, 500

5,300

500

72, 700

Total, 

1904.

S6, 000

42, 900

17, 000

500

5,000

02, 000

50, 500

16, 000

100

17, 400

500

232, 900

Previous 

to 1904.

810, 000

18, 000

133, 000

1,500

2, 000

8,500

23, 300

227, 000

9,000

800

2, 800

 879, 100

Total to 

fall, 1904.

$10, 000

150, 000

2,000

2,000

13,500

15, 000

85, 300

277, 500

25, 000

100

18, 200

3,300

1, 112, 000
INDEX.

A. Page. 

Archimedes sp., occurrence of.............. 22

Area of region.............................. 5,26

Aulacophyllum, occurrence of.............. 21

B.

Baker Creek, gravels on.................... 23

location and character of............. 9,12,15

' rocks on................................ 25

timber on............................... 16

Baker Creek group, description of.... 26,38-40,47

diggings of.............................. 38-47

gold of.................................. 47-48

. hydraulicking in........................ 49

production of........................... 39

rocks at..............................; . 39,47

summary of............................ 47

topography of.......................... 38-39

trails to................................ 39,47

Baker Flats, gold on....................... 27

location and character of............... 9,15

Barite, occurrence of .................... 33,38,48

Basalt, occurrence and character of....... 24

Beaver Creek, location and character of.. 9,12-14 

rocks on and near...................... 18,24

timber on............................... 16

topography on ; ........................ 9-10

Beaver Creek Chatanika River divide, description of..................... 0-10

Bed rock, character of..................... 16

Benches, occurrence of....,................. 28-29

Berries, abundance of...................... 16

Birch Creek formation, character of........ 17

Birch Crock region, work. in................ 5,7

Bison a.llcni, occurrence of.................. 35-36

Boothby Creek, location of................. 41

Boston Creek, location of................... 40

Brooks, A. EL, work of..................... 7

C.

Carboniferous rocks, occurrence and character of........................ 17,21-22

Chatanika River Beaver Creek divide, description of...................... 9-10

Cladopora sp., occurrence of .......^......... 21

Chapman Creek, gravels on................. 29

Chatanika River, location and character of.. 12 

rocks on................................ 18

timber on............................... 16

Chicago Creek, gold on..................... 45

Clay, ice mixed with........................ 45

Collier, A. J., on Minook Creek............. 28

work of................................. 7

Communications, character of.............. 6-7

Copper, occurrence of.................... 35,48-49

Coral sp., occurrence of..................... 22

Page. 

Creeks of region, location of................ 6

Sec also individual creeJcs.

Cretaceous rocks,charactcr and occu rrciiee of 17,21 

Cythcrella sp., occurrence of..............'.. 22

D. 

Dawson Creek, location of.................. 32

Devonian rocks, character and occurrence of 17-21 

Diabase, minerals from..................... 49

Dikes, ice, occurrence of.................... 33

Distarfccs, table of.......................... 49

Doric Creek, distance to.................... 49

freight rates to......................... 49

gold on.............................. 41-42,48

gold specimens from, view of........... 38

production of........................... 50

Drainage of region.......................... 12-15

Eagle Rock, character of................... 18

Elevations, character of.................... 8

Euomphalus sp., occurrence of............. 22

Eureka Creek, character of................. 40

distance to............................. 49

freight rates to......................... 49

gold on................................. 39-40

location and character of............... 15,39

mining on.............................. 40

production on.......................... 50

Evans, Thomas, fossil found by........... 36

Experimental farm, U. S., location of...... 16

Explorations, dates and character of....... 7

E. 

Favosites cpidermatus, occurrence of.......

limitaris, occurrence of.................

winchelli, occurrence of.................

Fenestella sp., occurrence of................

Fistulipora sp., occurrence of...............

21

21 

 21

22 

22 

Florida Creek, character of.............. 32,36-37

distance to............................. 49

freight rates to......................... 49

gold on................................'. 37

location Of.:............................ 31

production on.......................... 50

rocks on and near...................... 24

Folding, occurrence of...................... 20

Fortymilc formation, character of......... 17

Fortymile region, work in.................. 5,7

Fossil Creek, location and character of..... 13,31

Fossils, occurrence of................. 17,19-22,31

Freighting, rates for...................... 6,39,49

G. 

G arnets, occurrence of................... 37-38,48

Gazzam Creek, location and character of... 14

51
52 INDEX.

Page. 

Geography, account of..................... 8-10

Geology account of........................ 16-25

map showing........................... 5

summary of...................... 1..... 24-25

Girty, G. H., fossils'determincd by......... 21

Glcnh Creek, character and location of..... 15,43

distance to............................. 49

freight rates to......................... 40

gold of......'......................... 39,43,48

mining on.............................. 43

view of............................. 42

production on.......................... 50

rocks on................................ 24

view on................................. 42

Gold, character of.......................... 48

derivation of..................... 25,37,48-49

occurrence of........................... 48

types of............................. 48

production of........................... 27,50

relation of rocks and................... 25,49

specimens of, view of................... 38

value of.................................. 27

See also individual creeks, etc. 

Gold placers, distribution of, map showing. 26 

Gold Run, character of..................... 43-44

distance to............................. 49

freight rates to......................... 49

gold on................................. 44,48

production on.......................... 44,50

Golden Creek, view of...................... 10

Goodrich, H. B., work of................... 7

Goose Creek, location and character of..... 12

Granite Creek, flow of...............,.!.... 28

Granitic rocks, occurrence, and character of. 23-24 

Gravels, auriferous, depth of............... 27,49

occurrence of........................ 17,23', 48

map showing....................... 26

See also particular creeks, etc. 

Greenstones, occurrence and character of... 24 

Ground ice, occurrence of................... 33

Gunnison Creek, location of................ 48

Gypidula pseudogaleatus, occurrence of.... 21

H.

Hematite, occurrence of.................... 33,48

Hess, F. L., on gold placers of region....... 26-50

work of................................. 7-8

Hess Creek, fossils on..................... 17,21-22

gravels on.............................. .23

location and character of............. 9,12,14

rocks on and near...................... 24

timber on............................... 16

topography on.............."........... -10

High Bench, gold on........................ 31

origin of................................ 37

gravels of............................... 30-31

origin of............................ 31

location and character of............... 30

Hoosier Creek, character of.............. 31-32,36

distance to............................. 49

freight rates to......................... 49

gold on................................. 27,36

. mining on.............................. 36

production on.......................... 36,50

Hot Springs, farming at.................... 16

Hunter, William, gold found by............ 32

Page.

Hunter Creek, character of................. 31-32

copper on.....................;......... 48

distance to............................. 49

freight rates to......................... 49

gold specimens from, view of........... 38

gravels on.............................. 29,32

hydraulickiug on, view of...........:.. 32

ice on................................... 33

mining on.............................. 33

production on.......................... 33,50

rocks on and near....................... 24,32

Hustcdia compressa Meek, occurrence of... 22

Hutlina Creek, location and character of... 15,46 

timber ,on............................... 16

Hydraulickiug, use of...................... 49

water for............................. i. 46^7

IIce, dikes of................................ 33

occurrence of........................... 35,45

Ice, ground, occurrence of.................. 33,45

Idaho Bar, gold at......................... 31

views at................................. 30

Igneous rocks, occurrence and character of. 23-24

Interstrcam area, gold fields of............. 5-7

Itinerary................................... 7-8

J. 

Joe Bush Creek, location of................. 41

K.

Kenai formation, occurrence and character of 17,22 

Kindle, E. M., fossils determined by........ 21

Koonce, M. E., on Minook Creek........... 28

L. 

Labor, cost of.'.................."........... - 27

employment of......................... 49

Laiigford, Y.S., gold found by............. 26-34

Lima sp., occurrence of .................... 22

Lithostrotion sp., occurrence of............ 22

Little Minook Creek, character of.......... 31-34

copper on............................... 35,48

distance to............................. 49

freight rates to......................... 49

gold on........................ 26-27,34-35,37

gold specimens from, view of........... 38

ice on................................... 35

mining on.............................. 36

view of............................. 32

production on .......'.....I........:.... 34,50

rocks on................................ 34

silver on................................ 35

view on................................. 30

Little Minook Junior Creek, description of.. 35-36 

distance to............................. 49

fossils on.:.......................... 31,35-36

freight rates to......................... 49

gold on ...............I................. 27,36

location of.'............................. 31

mining on.............................. 36

production on.......................... 35, ,50

Location of region.......................... 5

Lumber, price of............................ 16,39

Lynx Mountain, drainage of............... 13-14

location and character of............... 11

rocks on and near................ 17,20,23-24
INDEX. 53

M. Page. 

McDonald Bar, gravels at.................. 31

McLean, Donald, estimate by.............. 35

fossilfounclby.......................... 35-36

Magnetite, occurrence .of ................... 48

Map, geologic, of region.................... 5

comment on............................ 8

Metamorphosed rocks, occurrence and character erf......................... 18-23

Michclina, occurrence of.............. I..... 21

Mining, character of........................ 27

Minook, John, gold found by............... 26,34

Minook Creek, distance to.................. 49

freight rates to.....'.................... 49

gold on, production of.................. 29-30

gradient of............................. 28

gravels on.............................. 23,28

view of.................^........... 30

location and character of.. 6,9,12,14-15,28-29 

mining on.............................. 30

placers on, description of............ 29-30,48

production on.......................... 50

rocks on and near.................... IS, 22-25

silver on, occurrence of.......:......... 30

tributaries of........................... 28

valley of, figures showing............... 29

Minook Creek group, description of........ 26-28

diggings of.............................. 28-38

hydraulicking on....................... 49

production of........................... 28

topography at.......................... 27-28

Montana Creek, gravels on................. 28

Monzonitic rocks, occurrence and character

of..........................^... 23-24

0.

Omega Creek, distance to...............:.. 49

freight rates to......................... 49

gold on................................. 45,48

gold specimens from, view of........... 38

location and character of......... 15,39,44-45

mining on .............:....... ......... 45

production on.......................... 50

rocks on................................ 24

P.

Passenger fares, rates of.................... 6

Peck, C. W., fossils found by.. ............ 36

Pennsylvania!! rocks, character and occurrence of...................... 17,21-22

Permo-Carboniferous rocks, character and

occurrence of................... 17,21

Pioneer Creek, character of..............:.. 40-42

gold on................................. 39

gravels on...............:\............. .41-42

location and character of............... 15

Placer districts, grouping of................. 26-27

Pleistocene gravels, character and occurrence of......................... 17

Polypora sp., occurrence of................. 22

Prindle, L. M., on geology and geography of

region.......................... 5-25

on hydraulicking....................... 46

on Minook Creek....................... 28

Production of region....................... 27-50

Productus sp., occurrence of ............... 22

Ptilodlctya frondosa, occurrence of........ 21

 Q. Page. 

Quail Creek, distance to.................... 49

freight rates to ......................... 49

gold on.............................. 27,47^18

location and character of............... 14,47

production of........................... 48,50

view on................................. 42

Quaternary rocks, occurrence and character

of.........;..........,:......... 17,23

n.

Rampart, history of........................ 5

location and character of................ 6

Rampart formation, character of.......... 17

rocks analogous to ..................... 19

Recent rocks, character of.................. 17

Relief of region, description of.......... '.... 9-11

Rhode Island Creek, bench near............ 44

location and character of............ 15,39,44

rocks on................................ 24

Rhc-mbopora sp., occurrence of............. 22

Ruby Creek, character of................... 37

distance to............................. 49

freight rates to......................... 49 

garnets on........................... 37,38,48

gold on. .......................... 27,37-38,48

gravels on.............................. 28-29

production on.......................... 37-50

rocks on .... 1........................ 20,29,37

S. 

Schradcr, F. G., work of.................... 7

Seattle Bar, gold on ........................ 42

gold specimens from, view of........... 38

Seattle Creek, character of................. 44

distance to............................. 48

freight rates to ...........:............. 49

gold of......I........................... 44,48

production on.......................... .50

Seattle Junior Creek, location of.....:..... 41

Sedimentary rocks, occurrence and character of........ i....:............. 18-23

Silurian rocks,-possible occurrence of....... 17,20

Silver, occurrence of............... 30,35,38,48-49

Skookum Creek, location of................ 41

Shirley Bar, gold at........................ 42,48

gold specimens from, view of........... US

location of............................... 42

Slate Creek, character of................... 38

copper on..................'............. 48

distance to............................. 49

freight rates to ......................... 49

'gold on.............................. 27,38,48

gold specimens from, view of........... 38

production on.......................... 38,50

Spirifer sp., occurrence of................... 22

Spurr, J. E., on pro-Devonian rocks........ 18

work of................................. 7

Squaw Creek, prospecting on............... 26

Stanton, T. W., fossils identified by........ 36

Stenopora sp., occurrence of................ 22

Stratigraphy, account of................... 17

Stromatopora, occurrence of............... 21-22

Supplies, route for.......................... 6

T.

Tanana River, creeks tributary to......... ' 9

Tanana-Yukon divide, character of ..... 8,10-11

Tertiary rocks, occurrence and character of. 17,22
54 INDEX.

Thanksgiving Creek, distar e to ........... 49

freight rates to ......................... 49

gold on.............................. 39,45-46

gold specimens from, view of........... 38

ice on...............;................... 45

location and character of............... 15,45

magnetite on...:....................... 48

production* on.......................... 50

Timber, character of....................... 16

Tolovana Flats, location and character of.. . 9 

Tolovana River, rocks on .................. 25

location and character of............... 9,12

topography on......................... 10

timber on............................... 16

Travel, difficulties of....................... 6-7

Troublesome Creek, location and character

 of............................... 14,47

rocks on and near................... 20-21,24

Troublesome Creek group, description of... 26,47 

diggings of.............................. 47-48

rocks of................................. 47

V.

Vegetation, character of.................... 16

Victoria Creek, location and character of... 13-14 

rocks on................................ 25

W. Page. 

Wages, scale of............................. 27

Water, supply of........................... 46

What Cheer Bar, gold on................... 41

gold specimens from, view of........... 38

mining on.............................. 41

White Mountains, description of........... 9-10

drainage of............................. 13

fossils of................................ 19,21

location of.............................. 8-9

rocks of................................. 24-25

views on................................ 10

Winter, character of........................ 27

Wolverine Mountain, drainage of.......... 13-14

fossils on............................... 17,22

location and character of............... 11

rocks on ............................. 17,22-23

Wright, R. H., gold collected by........... 46

Y.

Yukon Flats, fossils from near............. 21-22

location and character of............... 9

Yukon-Tanana divide, character of...... 8,10-11

Yukon River, creeks tributary to .......... 9

Zaphrentis, occurrence of: 21