Tungsten Deposits of 

the Hyder District 

Alaska

GEOLOGICAL SURVEY BULLETIN 1024-F

Tungsten Deposits of 

the Hyder District 

Alaska

By F. M. BYERS, Jr.j and C. L. SAINSBURY

MINERAL RESOURCES OF ALASKA

GEOLOGICAL SURVEY BULLETIN 1024-F

A description of the mines and 

prospects

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON j 1956
UNITED STATES DEPARTMENT OF THE INTERIOR 

Fred A. Seaton, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

for sale t>y thfe~Sttp«rIntfen~dfenr«f Documents, Ui S.X3overnment Printing Office

Ut ,.: " ,V,7 J ~,: " . .Wellington 25, D. Cr-. r . -- . -..-,.
CONTENTS

Abstract_______________________________________ 123

Introduction____________________________________ 123

General geology _________ _________________________ 125

Tungsten deposits.________________________________ 126

Distribution. _________________________________ 126

Localization of the tungsten deposits______________ 127

Mines and prospects.________________________________ 129

Riverside mine_______________________________ 129

Production. ________________________________ 129

Geology__________________________________ 129

Veins..__________________________________ 130

Ore bodies_______________________________ 131

Tenor of the Lindeborg vein...____________ 133

Suggestions for further exploration_____ __ 135

Last Shot group_______________________________ 136

Mountain View mine__________________________---- 137

Fish Creek property..__________________________ 138

Last Chance group. __ __________________________ 139

Monarch prospect-__________________________ 139

Bluebird prospect__ ___ ___ ________________ 139

Other prospects....__..._...____________________ 140

ILLUSTRATIONS

[All plates in pocket]

PLATE 13. Generalized geologic map of a part of the Hyder district.

14. Geologic map of the Lindeborg shear zone, Riverside mine.

15. Geologic maps of levels, Riverside mine.

16. Longitudinal projection of main workings in Lindeborg shear 

zone, showing distribution of scheelite, Riverside mine 

(1942).

17. Map and longitudinal projection of upper levels, Riverside 

mine.

18. Geologic map showing scheelite deposits of the Mountain

View property. 

FIGURE 15. Index map of Alaska showing location of the Hyder district. 124

TABLES

~ Page

TABLE 1. Recorded production of the Riverside mine__________ 129

2. Drill-hole data, Riverside mine___ __________ ___ 134

3. Partial analyses of vein cores from drill holes S3 and M18_ 134

in

MINERAL DEPOSITS OF ALASKA

TUNGSTEN DEPOSITS OF THE HYDER DISTRICT,

ALASKA

By F. M. BYEES, Jr., and C. L. SAINSBUEY

ABSTRACT

The Hyder district at the head of the Portland Canal in southeastern Alaska 

is about 750 miles north of Seattle, Wash. The recovery of gold and silver from 

Riverside, the only productive mine in the district, continued intermittently 

from 1925 to 1929, and many claims were staked nearby. With the high prices 

of tungsten prevailing during World War II, the Riverside was reopened to 

mine tungsten ore in 1941. During 1941-46, about 3,000 units (60,000 pounds) 

of WOa was produced. During 1947-51 the mine was primarily a producer of 

sulfide concentrates containing lead, copper, zinc, silver, and gold.

The tungsten mineral, scheelite, is in quartz sulfide veins in the Texas Creek 

granodiorite of Jurassic or Cretaceous age. One of the veins, the Lindeborg in 

the Riverside mine, is enclosed within a schist inclusion in the granodiorite, and 

ore shoots containing scheelite are most abundant in this vein. It is concluded 

that the schist inclusion was a zone of weakness at the time of mineralization 

and also was a favorable chemical environment for the deposition of scheelite. 

The Last Shot claims are on the apparent southeast extension of the Lindeborg 

vein, but they contain only sparse scheelite exposed in opencuts. The Fish 

Creek No. 2 vein of the Mountain View property is known to contain one shoot 

of scheelite ore and may contain others. Several other properties in the district 

contain seheelite-bearing quartz veins.

During the latter part of 1942 and the early part of 1943 the U. S. Bureau of 

Mines tested the Lindeborg vein of the Riverside mine tfy 4,660 feet of diamond 

drilling and by analyses of 93 ore samples. In 1944 the Bureau extended the lower 

drift for 180 feet on the Fish Creek No. 2 vein of the Mountain View property 

and analyzed 70 channel samples taken across the vein. On the basis of these 

analyses the average grade of tungsten ore shoots on the Riverside and Mountain 

View properties is slightly greater than 1 percent of WOs.

Much of the best ore has already been mined at the Riverside property; additional tungsten ore shoots of slightly lower grade than those already mined will 

probably be found at the depth and in the southeastern part of the vein, On the 

Mountain View property, the possibility of discovering additional ore shoots 

comparable in grade to the one now exposed is regarded as good.

INTRODUCTION

The Hyder district (fig. 15) is largely in the Salmon River drainage 

basin at the head of Portland Canal in southeastern Alaska. Tlfoe 

district has 22 miles of graded gravel road, connecting with mads in

123
124 MINERAL RESOURCES OF ALASKA

British Columbia to the towns of Premier and Stewart, both within 

2 miles of the international boundary. Premier is 13 miles by road 

north of Hyder. Stewart, with a population of 446 in 1950, has

FIOUBE 15. Index map of Alaska showing location of the Hyder district.

adequate dock facilities within 1 mile of Hyder. In 1950 Hyder had 

72 inhabitants.

Many claims were located from 1922 to 1929 during the peak of 

mining activity in the Hyder district. At that time the gold and
TUNGSTEN DfiPOStTS W THE HTfDMB DISTRICT, ALASKA 125

silver content of the base-metal concentrates was of primary interest, 

although the tungsten mineral, scheelite, was known to be present in 

some of the ores. On plate 13 all except one of the claims known to 

contain scheelite are shown. From 1930 to 1940 there was no mining 

in the Hyder district. In 1940 the J. H. Scott Co. of San Francisco 

purchased the Riverside mine, the only productive mine in the district, 

from H. C. Strong and J. C. Black, of Seattle, and began development 

work.

Owing to the high unit value of tungsten prevailing just before and 

during World War II, the milling procedure was modified to produce 

byproduct scheelite in 1941. About 3,000 units (60,000 pounds) of 

WO3 was recovered during the period 1941-46. Subsequently, however, the mine has been primarily a producer of lead-zinc-copper 

concentrates.

The senior writer worked in the district from June 3, 1942, to 

February 6, 1943. He was assisted by H. R. Gault until July 1, 1942, 

and by Clyde Wahrhaftig from August 12 to December 4, 1942. 

From October 27,1942, to February 6,1943, the U. S. Bureau of Mines 

diamond drilled, sampled, and drove an exploratory raise at the 

Riverside mine and sampled the Mountain View mine. 1 In the summer of 1944 the Bureau extended to the northwest the Skookum tunnel 

drift in the Mountain View mine. When the drift was stopped on 

October 24, 1944, it had been extended 180 feet to the position shown 

on plate 18.2

In September 1951, the junior author and Robert L. Thorne, of the 

Bureau of Mines, spent 8 days in the district and reexamined the 

Riverside mine and Last Shot claims. Considerable mining and 

underground exploration were done at the Riverside mine during 

1943-51, and a r6sum6 is included in the present report. The junior 

author is primarily responsible for collecting data covering the period 

1943-51 and for the description of the Last Shot claims.

Thomas Evans, Holger Johnson, Arthur Moa, and Sidney Anderson, 

of Hyder, assisted in the fieldwork. James Langdon, of the J. H. 

Scott Co., helped the junior author during his examination and made 

available all the reports of the company pertaining to the Riverside 

mine.

GENERAL GEOLOGY

A comprehensive report on the general geology of the Hyder district 

was prepared by Buddington 3 and published in 1929. From that

i Thorne, R. L., and others, 1948, Tungsten deposits in Alaska: U. S. Bur. Mines Kept. Inv. 4174, p. 40. 

* Idem., p. 47.

»Buddington, A. P., 1929, Geology of Hyder and vicinity, southeastern Alaska: U. S. Geol. Survey 

Bull. 807,124 p.
M2BEBRAL &SBOOBCES OF

report msmy of the general statements regi&nding the geology Jfoave 

been abstracted.

The oldest rocks of the district compose the Hazelton group, of 

Jurassic(?) age, and include greenstone schist, tuff, volcanic breccia, 

graywacke, slate, argillite, and quartzite. These rocks crop out 

abundantly between Salmon River and the international boundary. 

In general they strike west, but many exceptions to this general strike 

are seen, particularly near intrusive bodies.

The rocks of the Hazelton group are intruded by plutonic rocks of 

the Coast Range batholith, which are thought to be of Jurassic or 

Cretaceous age. The Texas Creek granodiorite, which forms a small 

batholith confined chiefly to the central portion of the district, is the 

oldest of the several Coast Range intrusives in the district. It is 

intimately and probably genetically related to most of the mineral 

deposits. Elongate bodies of sheared greenstone schist and argillite 

of the Hazelton group, up to at least 100 feet wide and 2,000 feet long, 

are included in the Texas Creek granodiorite. The largest known of 

these inclusions constitutes the Lindeborg shear zone at the Riverside mine.

Younger Coast Range intrusives include the Hyder quartz monzonite and the Boundary granodiorite. Granodiorite porphyry dikes, 

10 to 1,000 feet wide and related to the Hyder quartz monzonite, 

intrude the Texas Creek granodiorite and cut some of the scheelitebearing veins. Dikes of granite aplite, granite pegmatite, malchite, 

and lamprophyre cut all the batholith intrusives, the rocks of the 

Hazelton group, and the veins.

Veins and dikes are displaced by faults, such as the two faults 

followed roughly by Fish and Skookum Creeks (pi. 13). These two 

faults dip steeply westward. They have zones of gouge and breccia 

as much as 30 feet wide.

TUNGSTEN DEPOSITS 

DISTRIBUTION

Most of the scheelite known in the Hyder district is on the east 

side of the valley of Salmon River in an area about 1% miles wide and 

3 miles long, which begins 5% miles north of Hyder (pi. 13). Scheelite 

is known to be abundant in this area only on the Riverside and the 

Mountain View properties.

The scheelite-bearing deposits are mineralized shoots in quartz 

veins that cut the Texas Creek granodiorite and inclusions of the rocks 

of the Hazelton group in the granodiorite. Most of the veins strike 

N. 40°-60° W. and dip 50° to 80° NE. The veins, therefore, are at 

an angle to the gneissic banding of the Texas Creek granodiorite,
TUNGSTEN DEPOSITS OF THE HYDER DISTRICT, ALASKA 127

which in general strikes N. 85° E. and dips steeply northward. The 

scheelite-bearing veins are as much as 7 feet thick.

The ore minerals include scheelite, galena, pyrite, tetrahedrite, 

pyrrhotite, chalcopyrite, sphalerite, and native gold. Galena and 

pyrite are present hi nearly all the veins, and in some veins pyrrhotite 

makes up a notable part of the sulfide minerals. Sphalerite and 

chalcopyrite are present as accessory minerals in nearly all the veins, 

and small amounts of tetrahedrite and native gold occur in many of 

them. The principal gangue mineral is quartz; minor amounts of 

calcite, ankerite, and barite are also found.

Scheelite in small, sparsely distributed crystals is known in a few' 

deposits in the Hyder district and in adjacent British Columbia 

outside the 1% by 3-mile area described. A little scheelite 4 has been 

recognized in a vein on the Engineer group about 6 miles northwest 

of the Riverside mine. In the Hazelton group in British Columbia, 

between 4 and 6 miles southeast of the Mountain View property, 

scheelite has been recognized hi two replacement deposits and in a 

quartz vein containing tetrahedrite (W. H. Mathews, 1942, personal 

communication).

LOCALIZATION OF THE TUNGSTEN DEPOSITS

The localization of the richer scheelite-bearing veins in the Hyder. 

district has probably been controlled principally by the presence of 

schist inclusions in the Texas Creek granodiorite. According to this 

hypothesis, the schist inclusions not only constituted a zone of weakness along which fissuring took place but also contained calcareous 

bands that favored deposition of the scheelite.

No veins containing scheelite ore bodies are known in the mam 

rock mass of the Hazelton group surrounding the Texas Creek granediorite, probably because the Hazelton rocks, which are mainly 

altered tuffs, were not capable of retaining open fissures during tke 

time that mineralization was taking place elsewhere. Nearly all the 

scheelite-bearing quartz veins occur in the Texas Creek granodiorite 

near its contact with the Hazelton rocks. The Fish Creek No-. 2 

vein on the Mountain View property is within the granodiorite aaad 

contains scheelite in greater abundance than other veins that ase 

entirely within granodiorite. However, it is probable that scheelite 

was deposited in somewhat greater abundance in this vein, because 

schist inclusions, such as the one exposed in a pit on the surface akmg 

the vein fissure (pi. 18, inset 1), provided a, more favorable chemical 

environment for the deposition of scheelite than veins laeking such 

schist inclusions.

* BuddiagteB, A. F., op. cit., p. 110. 

388407 56 2
128 MINERAL RESOURCES OP ALASKA

The Lindeborg vein of the Riverside mine contains conclusive 

evidence of the effect of a schist inclusion on the deposition of scheelite. 

This vein is enclosed within schist (pis. 14 and 15), and it contains 

several scheelite ore bodies, which apparently are associated with 

certain zones within the schist. The vein is complex because it is hi 

part a fissure filling and in part a replacement vein. The part that is 

fissure filling resembles in texture and mineral content those veins, 

such as the Fish Creek No. 2 vein, which Occur hi granodiorite. In 

the typical fissure-filling vein type, large crystals of scheelite, several 

inches across, oectir in veins of white quartz. The deposition of 

scheelite was probably brought about by calcareous schist in the wall 

rock nearby. In the Fairbanks district, Alaska, the quartz veins 

almost invariably contain scheelite in places where the quartz veins 

are near or adjacent to calcareous wall rock. A similar explanation 

is suggested for the deposition of scheelite in parts of the Lindeborg 

and Fish Creek veins of the Hyder district.

The part of the Lindeborg vein that probably was formed by the 

replacement of scljist contains quartz with stringy bands of finegrained scheelite parallel to the schistosity. The scheelite apparently 

has selectively replaced some of the thin schist laminae that contained 

calcite. In the hanging-wall stope (pis. 15 and 16) of the Riverside 

tnine and elsewhere, epidote is a common mineral of the gangue. 

Inasmuch as both scheelite and epidote are common replacement 

minerals in calcareous rocks, it is inferred that hi the Hyder district 

these minerals wer^ deposited near or in calcareous bands in schist.

The order of deposition of the vein minerals in scheelite-bearing 

veins has been studied by Jewell 5 and the present authors. Most of 

the fine-grained scheelite-epidote-quartz replacement aggregate is 

fractured and cut by veinlets containing all the sulfide minerals in 

addition to quartz and a little scheelite. Hence, the periods of deposition of scheelite and part of the sulfide minerals appear to have 

overlapped slightly hi the second period of ore mineralization. The 

large masses of barren quartz exposed on the Riverside, Mountain 

View, and other properties were probably deposited at a still later 

period than the deposition of the sulfides and scheelite, for, in the 

upper level of th0 Riverside mine, stringers of barren quartz cut 

across both sulfides and scheelite in the Lindeborg vein. However, 

sulfide veinlets in the Last Shot claim (pi. 13) cut large barren quartz 

pods, similar to thpse on the Riverside property. Similar relations 

between sulfide veinlets and barren quartz have also been observed 

on the Olympia Extension vein on the Last Chance group (Clyde

Wahrhaftig, 1952, personal communication). Thus^ a sulfide min-

________ | « Jewell, W. B., 1927, Mineral deposits of the Hyder district, southeastern Alaska: Econ. Geology, v. 22, 

p.494r-517. ;
.TUNGSTEN DEPOSITS OP THE HTDEB DISTRICT, ALASKA 129

eralization occurred after the introduction of barren quartz in some 

of the veins that carry a little scheelite.

MINES AND PROSPECTS 

RIVERSIDE MINE

The Riverside mine is 7 miles north of Hyder and is on the east side 

of the Salmon River road. Slightly more than 1 mile of underground 

workings are now accessible on several levels, of which about 3,000 

feet are in the Lindeborg vein, the principal vein in the mine (pis. 14 

and 15). A mill, with a capacity in 1951 of 25 to 30 tons per day, and 

living ^accommodations for about 20 men are on the property.

PRODUCTION

The production data recorded for the period 1925-50 are given in 

table 1. In 1925, 105 tons of concentrates were produced from ore 

mined from the Cross vein stopes. Subsequent production has come 

from the Lindeborg vein. Seheelite is reported in the ore mined during 

1927 but was not recovered.

TABLE 1. Recorded production of the Riverside mine 

[From records of the Bureau of Mines and Geological Survey and information furnished by J. H. Scott Co.]

Year

1925. .....

1927 ___ _

1941 ___ _

1942 ___ _

1943.._.__

1944 _..___

1945 ......

1946 _ __.

1947___.__

1948. __ .

1949__. ...

1950 ___ .

Total. _.

Ore milled 

(tons)

2 105

6,500

3,368

1,381

1,300

1,819

5,064

4,005

2, 100

3,500

29, 142

Au 

(ounces)

419. 5

23

(3)

70

697

736

151

356

2, 452. 5

Ag 

(ounces)

15, 210

830

(3)

6,996

22, 284

25, 290

3,500

12, 700

86, 810

Cu

(pounds)

none

none

(3)

4,000

24, 000

28, 000

7,700

12, 000

75, 700

Pb 

(pounds)

460, 200

29, 000

(3)

230, 000

510, 000

634, 000

97,000

298, 000

2, 258, 200

WOs

(units) '

1,320

372

976

(3)

415

(4)

(4)

(4)

99

3,500

Zn 

(pounds)

(3)

2, 100

3,800

12,000

17,900

1 A unit is 20 Ibr. of WO3 .

2 Tons concentrate, grade unreported.

3 Not reported.

4 Small quantities of tungsten concentrates produced, according to Minerals 

Yearbook, 1947-49.

GEOLOGY

The main geologic feature of the Riverside mine is the Lindeborg 

shear zone (pis. 14, 15, and 16), an elongate sheared inclusion of schist 

and-argillite in the Texas Creek.granodiorite. Tongues of ,the gra.nodiorite have been intruded into the schist parallel, to the schistosity.

 - > \- ''.. . :. lu ..' :-m
130 MINERAL RESOURCES OF ALASKA

The zone strikes N. 45°-55° W. and dips steeply northward. It is 

exposed for about 2,000 feet along its strike and through a vertical 

interval of more than 700 feet. Toward the southeast end of its outcrop the shear zone splits and probably pinches out within a short distance. To the northwest the zone extends beneath the Salmon River 

alluvium. The extent of the zone downward is of economic significance, if, as seems probable, calcareous schist in the zone has caused 

the precipitation of scheelite. The zone is at least 80 feel thick on the 

mill level at an altitude of 320 feet (pi. 15) and more than 100 feet 

thick along the Salmon River road and in drill holes Si and S2 (pi. 14). 

Thus the zone does not diminish in thickness downward through its 

exposed vertical extent.

The Lindeborg shear zone is essentially a well-foliated schist inclusion along which some movement has taken place parallel to the foliation. The principal fault is now occupied by the Lindeborg vein; some 

movement has taken place along this fault since the emplacement of 

the vein. The schistosity of the metamorphic rocks of the Lindeborg 

shear zone is approximately parallel to the zone. The shear zone has 

within it no persistent stratigraphic or structural units other than the 

Lindeborg vein. The schist wall rock of the Lindeborg has been altered 

to sericite, quartz, and minor amounts of calcite and epidote.

A granodiorite porphyry dike and a smaller branch from it are exposed on the surface and in the underground workings, and are penetrated by some of the diamond-drill holes. The large main dike strikes 

about N. 10° W. and dips west (pis. 13 and 14). This dike probably 

cuts the Lindeborg vein a short distance southeast of the face of the 

upper level drift (pi. 16). The smaller branch dike strikes about N. 

40° W. and dips steeply southward at the surface (pi. 14). At depth 

it encounters the Lindeborg shear zone, where its dip is reversed to 

steeply northward parallel to the schistosity.

Thin lamprophyre dikes strike generally parallel to the schistosity 

of the shear zone. Malchite dikes cut the shear zone approximately 

in the middle of its exposed length (pis. 13, 14, and 15). A postmineral fault along the Lindeborg vein has displaced the malchite 

dikes about 20 feet horizontally (pis. 14 and 15). The pitch of 

striations and the displacement of the dikes indicate that the hanging 

wall shifted about 28 feet, 45 degrees downward to the southeast. 

An attempt was made to trace this fault southeast of the malchite 

dikes along the vein, but within 100 feet the displacement is taken up 

along numerous small parallel faults, none of which could be traced 

more than 50 feet.

VEINS

The Lindeborg shear zone contains the Lindeborg vein, which is 

not a single continuous vein but a mineralized zone containing dis-
TUNGSTEN DEPOSITS OF THE HTDER DISTRICT, ALASKA 131

continuous mineralized quartz veins and stringers. This vein or 

mineralized zone is generally nearer the footwall of the shear zone 

(pis. 14 and 15). The vein in its leaner portions consists of pyritized 

schist or of quartz stringers in a network as much as 6 feet wide with 

sparse grains of scheelite and sulfide minerals. The large elongate 

mass of quartz that crops out just below the upper tunnel adits (pi. 14) 

is barren of scheelite and is probably younger than the scheelite 

mineralization. The richer portions consist of a quartz vein as much 

as 7 feet thick, which contains sulfide minerals and scheelite. Below 

an altitude of about 500 feet the Lindeborg vein splits downward 

(sections, pi. 16). The separate vein segments just below the split 

are narrower than the vein above. At the mill level (altitude 320 

feet), however, two vein segments are less than 8 feet apart (pi. 15), 

and they may represent a further branching of the footwall vein 

observed on the intermediate level. At the face of the northwest 

drift (altitude 320 feet) the hanging-wall part of the vein contains a 

Bcheelite ore shoot, and a large shoot of seheelite-bearing ore formerly 

occupied the large empty stope just above the northwest drift. Thus 

it would appear that the Lindeborg vein or vein segments may continue to contain scheelite shoots with depth if, as seems probable, 

calcareous layers in the Lindeborg zone appear to have caused 

precipitation of the scheelite.

Other veins in the mine include the Cross and Ickis (also called the 

Biverview) veins, which are in Texas Creek granodiorite (pi. 15). 

The Cross vein, exposed on the mill level for 750 feet, has produced 

sulfide ore but contains only rare grains of scheelite. The Ickis vein, 

exposed in the mill level for about 260 feet, contains a few scheelite 

crystals within 100 feet of the portal. No production has come from 

the Ickis vein. The sparse quantities of scheelite in the Cross and 

Ickis veins, which are entirely within the Texas Creek granodiorite, 

provide negative evidence that seheelite in commercial quantities has 

been precipitated by calcareous bands in the Lindeborg shear zone.

ORE! BODIES

At least five scheelite ore bodies, all of which are partly or entirely 

mined out, are known in the Lindeborg vein. The largest ore body, 

the extent of which has been determined mainly by diamond drilling, 

extends about 60 feet northwest and 90 feet southeast of the east 

raise on the upper level (pis. 16 and 17) and nearly 200 feet above and 

possibly as much as 100 feet below the level. Approximately one-half 

of this ore body was removed during 1945-50. The ore body dips 

northeastward, steepening from 50° or 60° at the top of the east raise 

to about 70° at the floor of the upper level, and appears to rake 

southeastward. It w here called the east ore body, in accordance
132 MINERAL RESOURCES OF ALASKA

with the usage of the U. S. Bureau of Mines. Judging from the 

exposures in the upper level, in the east raise, and from diamond-drill 

 cores, both scheelite and galena are more abundant in the upper part 

of the ore body, 50 to 150 feet above the upper level. The inferred 

outline of the east ore body shown on plate 16 contains some barren 

portions, and the vein within this body ranges hi thickness from about 

half a foot to slightly more than 7 feet.

A second ore body, which was opened by the footwall, hanging-wall, 

and intermediate level stopes (pi. 16), was nearly mined out during 

1941. The lean margin of this ore body is partly exposed between 

the intermediate level and the hanging-wall stopes and in the back of 

the intermediate level stope (pi. 16). Fifteen feet above the intermediate level the ore body splits downward (section B-B*', pi. 16). 

It is reported that the quartz vein was 2 to 3 feet thick at the intermediate level and thinned to about 1 foot in the footwall and hangingwall stopes. In several large specimens of the mined-out vein the 

scheelite is segregated in a nearly solid band, 2 to 4 inches thick, in 

quartz. In several other ore specimens from this body small grains 

of epidote were observed in the gangue.

The ore that was removed from the overhead and underhand stopes 

near the face of the northwest drift and the ore now assumed to be 

present beneath the underhand stope is referred to as the west ore 

oody (section A-A', pi. 16), hi accordance with the Bureau of Mines 

usage. The ore body is a white vitreous quartz vein containing large 

crystals of scheelite as much as several inches across, with pyrite and 

barite. The vein is from YZ to 3% feet thick, but it has an average 

thickness of 2% feet. It extends for 33 feet in the bottom of the 

underhand stope and is exposed for several more feet to the northwest 

in the northwest drift. Drill hole Si penetrated barren schist 50 

feet below the ore body.

A fourth scheelite ore body is shown by the seheelite exposed in the 

pillars between the lower sublevel of the upper level and the upper 

tunnel level (pi. 17). The probable shape of the original body in 

longitudinal projection is an ellipse whose axes are 80 by 125 feet. 

The vein containing the scheelite. ore ranges in thickness from 1 foot 

to 4 feet; its average thickness is about 3 feet. About 50 percent of 

. this body remains; it appears to rake southeast. The barren portions 

of the ore body may aggregate 50 percent of the total volume. It 

seems that very little of the scheelite in this ore body was recovered 

because the ore was milled primarily for lead, gold, silver, and copper. 

This ore body is designated the upper sublevel ore body of the upper 

level in accordance with local usage.

A fifth ore body herein called the upper stope body of the uppfer 

tunnel level is suggested by the scheelite exposures in.the upper stope
TUNGSTEN DEPOSITS OF THE HYDER DISTRICT, ALASKA

of the upper tunnel level (pi. 17). The vein in the opencuts above 

(pis. 14, 16, and 17) contains a veinlet of solid galena and sparse 

scheelite, which may be the lean extension of this body. The southeast limit of this body has not been determined, but, judging from 

the dimension of the other scheelite bodies in the mine, it probably 

does not extend more than 50 to 60 feet beyond the southeast heading 

in the stope. Exposures are insufficient to define this body; hence it 

is inferred as an ellipse (pi. 17) with a surface cutoff midway between 

the underground ore and the sparse scheelite in the opencuts above. 

The scheelite in this ore body occurs as narrow high-grade bands in 

white quartz. Little of the scheelite from this ore body was recovered,, 

because the mine was under lease during the mining of the upper 

stope of the upper tunnel level, and the lessees milled the ore primarily 

for lead, silver, and gold. Some scheelite-bearing quartz was handsorted from the lead ore and thrown on the dumps.

In addition to the principal known scheelite-bearing bodies it is 

probable that the sulfide ore mined in 1927 from the large stope abovethe northwest drift (pi. 16) contained considerable scheelite. Scheelite-bearing quartz is exposed in many places about the margins of 

the stope. It has been reported by local miners that a heavy white 

mineral, presumably scheelite, was observed on the mill tables in 1927 

but was not recovered.

TENOR OF THE LINDEBORG VEIN

The Lindeborg vein in the Lindeborg shear zone has been tested 

by 41 drill-hole samples and 52 channel samples taken by the U. S, 

Bureau of Mines. The east and west ore bodies (sections D-D' and 

A-A'', pi. 16) have been sampled more extensively than the others. 

Vein samples containing WO3 have also been taken outside the known 

ore bodies in the mine.

The diamond drilling, totaling 4,660 feet, consisted of 37 holes that 

were started from underground stations and 4 holes that were started 

from stations on the surface. Analyses were made of 36 samples of 

scheelite-bearing drill cores and 47 sludge samples. In most of the 

drill holes the core recovery was 95 percent or more. Sludge analyses 

that are lower than the corresponding core analyses are not considered in the computation of grade in the present report. Sludge 

analyses from 3 drill holes (holes M2, M32, and M34) in which core 

was lost are included. The data from the drill cores obtained by the 

Bureau of Mines are summarized in table 2. Data from 16 drill 

cores that contain no scheelite are omitted from the table. Cores from 

drill holes S3 and Ml 8 were also analyzed for other metals by the 

Bureau and the results of these analyses are given in table 3.
134 MINERAL RESOURCES OP ALASKA

The location and WO3 content of the 52 channel samples taken by 

the Bureau of Mines are shown on plate 16. These data are supplemented by one analysis of a channel sample taken by the Geological 

Survey. The calculated average WO3 content of selected parts of 

the ore bodies is shown on plate 16 by bracketing the samples included 

in the average.

TABLE 2. Drill-hole data, Riverside mine 

[Data from U. S. Bureau of Mines]

Drill-hole no.

S2..............

S3... .......... .

84... ...........

M2.............

M6........._._.

M7_.... .....

MS............

M10-. ........

M15 .........

M16............

M17..-.... .

M18 .-. ..

M19-.--.-.. ...

M21............

M25-. ........

M28 ... ...

M29...... __ ..

M32»_. ........

M33-... .......

M34»... _ ....

M36......... ...

Depth of 

sample to 

hole 

(feet)

260. 5-260. 7

421. (M23. 0

423.0-425.0 

425.0-427.3 

299.0-299.3

299. 3-301. 8 

301. 8-302. 0

54.0-59.5

73.0-73.4 

7. 4-7. 6

4. 8-6. 0

7. 7-7. 9

7. 5-7. 7

59. 0-61. 0

57. 5-60. 3

60.3-62.0 

74. 5-78. 0

78. 0-82. 2 

88. 5-94. 8

94. 8-97. 6 

97. 6-100. 0 

100. 0-103. 0 

103. 0-106. 2 

106. 2-109. 8 

90.7-93.0

93. 0-97. 4 

97. 4-98. 8 

98. 8-101. 0 

101.0-106:0 

106. 0-107. 0 

3. 4-3. 5

36. 6-37. 2

82. 5-86. 0

105. 0-105. 4 

128.0-135.2

20. 0-25. 0

40. 4-41. 0

30. 0-35. 0

35.0-40.0 

35.5-38.0

Distance 

sampled 

(feet)

0.2

2.0

2.0 

2.3 

.3

2.5 

.2

5.5

.4

.2

1.2

.2

2.0

2.8

1.7 

3.5

4.2 

6.3

2.8 

2.4 

3.0 

3.2 

3.6 

2.3

4.4 

1.4 

2.2 

5.0 

1.0 

.1

.6

3.5

.4

7.2

5.0

.6

5.0

5.0 

2.5

Percent 

ofWOs

0.40

.15

7.70 

.36 

.25

None 

.16 

/ .67

I .15 

1.12 

.04

.11

.50

.28

05

.03 

1.43

.20 

.05

.03 

.15 

8.30 

1.23

1.78 

.67

.03 

.04 

.03 

.03 

.03 

.61

.20

1.18

.80 

.03

.05

.05

.03

.04 

.10

Total 

distance 

sampled 

(feet)

0.2

6.3

3.0 

} 5.5

'.2

1.2

.2

.2

9 n

X 45

f :t* u

} "

21.3

16.3 

.1

.6

.4

7.2

5.0

.6

} la ° 

2.5

Estimated 

angle, hole 

to vein

80°

80°

80° 

65°

65° 

80°

80°

80°

70°

CrtO

45

17°

26° 

60°

70°

27°

27° 

17°

50°

30°

30° 

V

Calculated 

vein thickness

0.2

6.1

2.» 

5.0

.4

.2

1.2

.2

.2

1.5

3.0

o. o

6.2

7.3

.1

.6

1.6

.2 

2.3

3.8

.3

5.0 

.3

Weighted

percent of 

WOs

0.40

2.60

.04 

1.20

1.12 

.04

.11

.50

.28

.57

.04

.76

1.68

.14 

.61

.2D

1.18

.80 

.03

.05

.05

.04 

.10

i Combined core and sludge analysis. 

* Sludge analysis.

TABLE 3. Partial analyses of vein cores from drill holes S3 and M18, Lindeborg vein 

[Data from U. S. Bureau oi Mines]

Drill-hole no.

S3_. .--_-____..__.. ___ ._ __ _

M18... ----_ __ _---______

Lead 

i (percent)

4.05

3.58

Copper 

(percent)

None

Silver 

(02 per tod)

4.79

Gold 

(oz per ton)

o. 017
TUNGSTEN ^WBPO^TS OF TgQH Hyj>E« J#ST,RICT, ALASKA

Only A generalized statement of grade is justified, because the grade 

ranges widely and changes abruptly and because the locations of the 

numerous drill-holes are not evenly distributed throughout the ore 

bodies. The ore in the east ore body-above the upper level, according 

to & weighted average, contains slightly more than 1 percent of WO3, 

and ore below the upper level averages slightly less than 1 percent of 

WO8 ; therefore an average grade of about 1 percent of WO3 is indicated for the entire body as outlined on section D-D' of plate 16. 

The average grade of ore samples from the west ore body is computed 

from the 9 channel samples taken in the bottom of the underhand 

stope of the northwest drift (section A-A'}. The samples average 

1.3 percent of WO3 across an average vein thickness of 2.4 feet and 

along an exposed strike length of 36 feet.

SUGGESTIONS FOR FURTHER EXPLORATION

The scheelite ore in the east ore body can probably be recovered 

during continued mining of the sulfide ore, which has been the principal product of the Riverside mine. A raise from the end or a 

slight extension of the southeast drift of the mill level could be expected to intersect the bottom of the east ore body indicated by the 

Bureau of Mines drilling (pi. 16). Below an altitude of about 480 

feet, two veins are present. Hence a sublevel along the Lindeborg 

vein at 475 feet, slightly below the split, would explore the most 

potentially productive part of the vein between the upper level and 

the southeast drift of the mill level.

The prospects of discovering an additional scheelite ore body or 

bodies in the part of the vein southeast of the workings above the 

upper level (pi. 17) is regarded as fair. The upper tunnel level and 

the lower sublevel of the upper level each could be extended southeast 

for a few hundred feet to the intersection of the postmineral granodiorite porphyry dike with the vein. On the basis of surface mapping 

(pis. 13 and 14), however, the Lindeborg shear zone decreases considerably in thickness southeast of the opencuts. Therefore, if the 

Lindeborg shear zone localized the scheelite ore shoots already discovered in the Riverside mine, any ore bodies discovered southeast 

of the present workings are likely to be smaller and lower grade.

The finding of additional ore shoots in the Lindeborg vein below 

the mill level is regarded as speculative, for the Lindeborg vein may 

further split downward; moreover four of the five drill holes that 

intersected the vein below the mill level did not contain scheelite. 

The width and grade of the vein below the mill level could be further 

tested by drilling several diamond-drill holes from surface stations 

near the Salmon River road (pi. 14) and from the drift of the Cross 

vein south of its intersection with the Lindeborg shear zone (pi. 15).
136 MINERAL RESOURCES OF ALASKA

The Lindeborg vein also could be explored at depth by dewatering 

the two winzes on the Cross vein (see composite map, pi. 15) and 

drilling a fan of diamond-drill holes from stations at the bottoms of 

the winzes, or by driving a drift on the Cross vein from the bottom 

of the winzes northward to the intersection of the Lindeborg vein. 

Such a drift would be a working drift for any possible ore discovered 

and would allow the gravity mining of any scheelite ore bodies discovered in the Lindeborg vein below the mill level.

LAST SHOT GROUP

The Last Shot group of 2 claims adjoins the Riverside claims on 

the southeast extension of the Lindeborg shear zone. An examination was made in 1951 of the adit on the southeast part of the property. 

(See pi. 13.)

The adit, 20 feet long, is driven east on a vein striking N. 60° W. 

and dipping 45° NW. The vein in the center of the adit consists of 

as much as 18 inches of massive galena, pyrite, and chalcopyrite. 

The hanging wall is a silicified talcose schist that contains a few scattered grains of scheelite through a thickness of about 3 feet adjacent 

to the sulfide vein. The footwall is dense quartz with scattered 

pyrite. The schist is a small remnant in a massive quartz pod similar 

to but much larger than the quartz pod between the upper level and 

the upper tunnel level at the Riverside mine. Twenty feet southeast 

of the drift, the vein continues into this quartz pod with galena and 

chalcopyrite as much as 8 inches wide. A small reverse fault striking 

N. 10° E. and dipping 80° N. displaces the vein about 8 inches. An 

analysis by the Bureau of Mines of a channel sample 26 inches long 

across the slant width of the sulfide vein is as follows: gold, 0.08 

ounce per ton; silver, 11.3 ounces per ton; 6.2 percent of lead; and 

4.85 percent of copper.

The northwest extension of the vein is traced on the surface 200 

yards by 4 opencuts. Three of the cuts contain galena, pyrite, and 

chalcopyrite in a vein at least 8 inches wide. The similarity of the 

mineral aggregate in the vein to the Riverside sulfide ores, and its 

apparent location on the same shear zone, suggests the possibility 

that scheelite ore bodies may also be found on the Last Shot group 

of claims as far southeast as the adit. However, no great thickness 

of schist, analogous to the Lindeborg shear zone, is associated with 

the Last Shot vein. Hence, it is believed unlikely that scheelite ore 

bodies, comparable in grade to those in the Riverside mine, will be 

discovered, although sulfide ore bodies may well be present.
TUNGSTEN DEPOSITS OF THE HYDEK DISTRICT, ALASKA 137 

MOUNTAIN VIEW MINE

The Mountain View mine is 5% miles north of Hyder between Fish 

and Skookum Creeks (pi. 13). The property has been described by 

Buddington 6 who recognized scheelite in one of the veins. From 

1925 to 1929 a total of 3,600 feet of tunnels were driven at the Mountain View mine. Of these workings, 3,500 feet are on the Skookum 

tunnel level at an altitude of 540 feet (pi. .18). Buildings on the 

property consist of a bunkhouse for 12 men, a water-wheel powerhouse, and several small sheds for storage of equipment. The mine 

is principally in Texas Creek granodiorite within a few hundred feet 

west of the contact with the main body of rocks of the Hazelton 

group (pi. 13).

The only vein that contains scheelite is the Fish Creek No. 2 or 

"Gray Copper" vein (pi. 18), which is wholly within the Texas Creek 

granodiorite, except for small schist inclusions of the Hazelton group 

along the footwall (pi. 18, inset 1). The vein strikes N. 45° W. and 

dips 50° N. It is exposed on the surface for 480 feet by several 

opencuts and in shallow underground workings by a 50-foot shaft 

and a 60-foot drift. Pits to the southeast that were dug on the surface along the projected trend of the vein do not reach bedrock. In 

the Skookum tunnel drift the vein has been followed for 300 feet.

The principal ore minerals in the Fish Creek No. 2 vein are pyrite, 

pyrrhotite, and scheelite with some chalcopyrite, galena, and a little 

sphalerite, tetrahedrite, and freibergite. The gangue is mostly quartz 

with a little barite. The vein also carries some gold and silver.

The following average grade estimates are based on sampling data 

by Aner W. Erickson, of the U. S. Bureau of Mines.7 In 1944 the 

northwest drift of the Skookum tunnel was extended by the Bureau 

for 180 feet, and 43 channel samples were taken underground on the 

Fish Creek No. 2 ("Gray Copper") vein (pi. 18, inset 4). The weighted 

average WO3 content of these 43 channel samples is 1.23 percent 

across an average vein width of 1.4 feet and along a strike length of 

130 feet. As analyzed by the Bureau,8 this ore also averages 0.1 and 

6.4 ounces per ton of gold and silver, respectively. The Bureau also 

took 27 samples 9 of scheelite-l^earing portions of the vein in the upper 

tunnel drift and in the surface exposures (pi. 18). The scheelitebearing portion of the vein in the upper drift and in the surface cuts 

above the drift (pi. 18, inset 2) contains a weighted average of 0.15 

percent of WO3 across an average width of 1.9 feet and along a strike 

length of 60 feet. Channel samples across the vein in other surface 

exposures contain as much as 3.93 percent of WO3 (pi. 18, inset 3), but

 Buddington, A. F op. dt., p. 63-67.

i Thorne, R. L., and others, op. cit., pi. 45-48.

8 Idem, fig. 19.

* Idem, figs. 17 and 20.
138 MINjaRAX- RESOURCES OF ALASKA

ore of this grade is confeed te small hjgh-p)84e shoots only a few feet 

in length.

Additional ore shoots may possibly exist in the Fish Creek No. 2 

vein between the Skookum tunnel drift and the vein exposures at the 

surface. One possible means of exploration would be to raise on the 

vein from the Skookum tunnel drift to the surface. Sublevels from 

this raise at appropriate intervals would explore the vein along the 

strike. The downward extent of the ore shoot exposed in the Skookum 

tunnel drift could be tested by a fan of drill holes from a station at the 

face of the Skookum tunnel crosscut on the northeast or hanging-wall

side of the vein.

FISH CHEEK PROPERTY

On the Fish Creek group of claims along the east bank of Skookum 

Creek (pi. 13) two veins in Texas Creek granodiorite near the rocks of 

the Hazelton group contain sparse scheelite. At an altitude of about 

1,600 feet, adit 3 has been driven southeastward for 60 feet on a 

quartz vein that strikes N. 35° W. and dips 65° N. The vein is 4 feet 

thick at the adit portal but pinches out 10 feet above it. About 20 

feet in from the portal, the vein splits into a network of quartz stringers. Scheelite occurs as scattered small crystals in the quartz for 40 

feet along the drift. The vein is estimated to contain less than 0.1 

percent of WO3 .

According to Buddington: 10

about 350 feet northeast of this vein (adit No. 3) * * * is another vein, which has 

been prospected by three adits (Nos. 4, 5, and 6) at altitudes of about 1,930, 1,900, 

and 1,800 feet, with lengths of 60, 109, and 185 feet, respectively. The vein 

strikes N. 50° W. and dips 45°-50° NE. Its width at the portals of the three 

adits is 19, 24, and 15 inches. A raise connects the middle and upper adits, and 

the vein has been partly stoped for 30 feet above the upper adit. In these upper 

workings it averages less than a foot in thickness but contains shoots of ore up to

the full 

*******

width.

The visible sulphides comprise galena and pyrite with tetrahedrite, sphalerite, 

and a little chalcopyrite.

The adits are mostly in granodiorite, but near their faces a fault 

separates the granodiorite from rocks of the Hazelton group and cuts 

off the veins. Minor amounts of scheelite are in the vein in all the 

adits. Adits 4 and 6 expose only sparse grains, but in the first 40 feet 

of adit 5 a 3-inch quartz-scheelite stringer is next to the quartz 

sulfide vein. This stringer is estimated to average between 1 to 2 

percent of WO3 for about 20 feet along the strike. The scheelite is in 

distinct crystals as much as 1 inch across. From 40 to 80 feet in from 

the portal the scheelite is sparse, and the stringer probably contains 

less than 0.1 percent of WO3 .

w Buddington, A. F., op. clt., p. 69.
TUNGSTEN DEPOSITS OF THE HYDER DISTRICT, ALASKA 139 

LAST CHANCE GROUP

The Last Chance group (pi. 13) is on the ridge between Skookum 

Creek and Salmon River at an altitfccte bfflween 2,600 and 2,900 feet 

and about 1 mile east of the Riverside mine. The Last Chance 

claims, formerly known as the Olympia Extension claims, are described by Buddington.11 The underground workings comprise 700 

feet of tunnels, a 50-foot raise, and two 50-foot winzes. The winzes 

are now filled with waste rock.

The vein known as the Olympia Extension, has been traced on the 

surface for several hundred feet by means of a series of opencuts and 

is exposed underground for a total distance of 180 feet along the 

strike in 2 drifts, which are 25 feet and 75 feet below the outcrop and 

90 feet and 100 feet long, respectively. The east end of the upper 

drift and the west end of the lower drift are connected by the 50-foot 

raise. The vein in the lower drift averages 1 foot thick and contains 

sparsely distributed grains of scheelite for a length of 50 feet; the grade 

of this part of the vein is estimated to be about 0.05 percent of WO3 . 

In the upper drift and on the surface above the upper drift the vein is 

3 to 4 feet thick and is well mineralized with galena, tetrahedrite, 

chalcopyrite, and sphalerite. Several small crystals of scheelite were 

seen in the upper drift, but examination of the surface cuts with the 

ultraviolet lamp failed to reveal any scheelite.

MONARCH PROSPECT

A 30-foot drift on the Monarch group of claims, has exposed a 

quartz veinlet containing scheelite, which may be part of the Olympia 

Extension vein that crops out 1,000 feet to the southeast. The 

veinlet, which averages 4 inches in thickness, is exposed in the face 

and along the drift except for a short interval 10 feet from the face. 

It is estimated to range in grade from 0.5 to 3.0 percent of WOS 

throughout its exposed length. A surface cut on a fissured zone 

above the drift failed to show any scheelite when examined with the 

ultraviolet lamp.

BLUEBIRD PROSPECT

In October 1942, the Bluebird claim (pi. 13) was located by Arthur 

O. Moa. Only hand specimens of the ore were examined. It is 

reported to be in the Texas Creek granodiorite about 1,500 feet west 

of rocks belonging to the Hazelton group and at an altitude of about 

2,300 feet. According to Mr. Moa, the vein is exposed for only a 

few feet and is 4 inches wide. It contains quartz with sparsely 

disseminated pyrite, chalcopyrite, galena, and scheelite in the central

" Buddington, A. F.( op. cit., p. 69-71.
140 MINERAL RESOURCES OP ALASKA

part; molybednite is present along its walls. Three hand specimens 

of the vein were estimated to contain about 0.5 percent of WO3 .

OTHER PROSPECTS

Scheelite occurring as rare grains was observed on the Brigadier 

(Hyder Butte), Liberty, Bear (Lucky Boy Extension), AlaskaPremier (south workings only), and Engineer prospects. The latter 

is outside the area shown on plate 13. Search with an ultraviolet 

lamp failed to reveal scheelite on the Helen (Howard), Six Mile, 

Cantu, Hyder Skookum, Titan, Cripple Creek, Daly-Alaska, 96, 

Texas Discovery, Hyder Lead, Morning, Lake, Blasher, Edelweiss, 

and Jumbo prospects. Many of these are outside the area shown on 

plate 13.

O M U