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Those too large to be entirely included in one exposure are filmed beginning in the upper left hand corner, left to right and top to bottom, as mony frames as required. The following diagrams illustrate the method: Un des symboles suivants apparaftra sur la dernlAre image de cheque microfiche, selon ie cas: le symbole — ► signifie "A SUIVRE", le symbole V signifie "FIN". Les cartes, planches, tableaux, etc., peuvent Atre film6s A des taux de reduction diff^rents. Lorsque le document est trop grand pour Atre reproduit en un seul clichA, 11 est filmA A partir de Tangle supArieur gauche, de gauche A droite. et de haut en bas, en prenant le nombre d'images nAcessaire. Les diagrammes suivants illustrent la mAthode. 1 2 3 1 2 3 4 5 6 r .a M GE« Prb / 6^9 DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY CHARLES 0. WALCOTT, DIRECTOR MAP OF ALASKA SHOWD^G KNOWN GOLD-BEABING ROCKS WITH DESCRIPTIVE TEXT CONTAINING SKETCHES OF THE GEOGRAPHY, GEOLOGY, AND GOLD DEPOSITS AND ROUTES TO THE GOLD FIELDS PRBPAKBD II« ACCOBDANCR with PuBMO RBSOL^mON No. 8 OF THK FlPTY-PIPTH C0NORK88 SBOOND BB88ION, APPROVBD J>J(UARV SW, 189H PRINTED IN THE ENQRAVINO AND PRINTINQ DIVISION OP THE UNITED StATES QEOLOQIGAL SURVEY WASHINQTON, D. C. 1898 r • • ••• • • • • » • ♦ • • > • > ,•» » • » «, . ^ A 9 « » , brouj prov( Alasl Me I)er80 Hon, LETTER OF TRANSMITTAL. Department of the Interior, United States Geological Survey, Washington, D. C, February 2, 1898. Sir : In accordance with your instructions, I have somewhat hastily brought together in the following pages such facts as seem likely to prove of immediate use to the prospetitors and miners who may visit Alaska. Messrs. W. H. Dall and F. C. Schrader, both of whom have I)ersonally studied the region, have rendered efficient aid in this work. Very respectfully, Your obedient servant, S. F. Emmons, Geologittt, Hon. Charles D. Wah-ott, Director United Stales Geological Survey. ^'StSt. CONTENTS. Introduction . Geographical sketch Rivera Climatic conditions Routes to Klondike Geological sketch . Physical description Original deposits, or quartz veins Detrital or placer deposits Probable extent of gold-bearing deposits Other metals than gold .... Coal and lignite Page. 5 7 8 10 11 18 itf 21 28 35 88 89 MAP OF ALASKA, WITH DESCRIPTIVE TEXT. INTRODUCTION. Alaska was first visited by a Rnssian expedition under Bering in 1741. In 1799 the territory was granted to a Busso- American fur company by the Emperor Paul VIII, and in 1839 the charter was renewed for twenty-four years. In 1867 it was ceded to the United States for a money payment of $7,200,000. The treaty was signed on March 30 and ratified on June 20, 1867; on the 18th of October fol- lowing, formal transfer of the country was made to the military force of the United States at New Archangel, now called Sitka. For a long time the wisdom of the purchase of this bleak tract of unknown land lying largely within the Arctic Circle was seriously questioned, and Mr. Seward, under whom, as Secretary of State, the negotiations for its purchase were conducted, was subjected to some criticism, even ridicule, in consequence. But the energy of the American people would not allow even so unpromising a region to remain idle. First, the seal fisheries on the Pribilof Islands were made to yield a considerable revenue to the Government. Then valuable gold mines were discovered and successfully worked in the islands of the Alexander Archipelago and along the adjoining coast, where the climate was found to be relatively mild and the proximity to deep and well -protected harbors facilitated the cheap mining and reduction of the ores. Gradually a few venturesome prospectors found their way across the mountains into the higher and far colder regions of the interior. The first mining excitement in the interior was in the Cassiar mining district in British Columbia around Dease Lake, near the head of the Stikine River, from 1871 to 1887. Later, prospectors found their way into the more northern regions and down the valley of the Yukon into American territory, where they dis- covered valuable phicers on Birch Creek, Mission Creek, and Forty- mile Creek, small southern tributaries of the Yukon. In the autumn of 1896 still richer discoveries were made a short distance east of the boundary, along the Klondike River, and a great rush of miners to these now famous diggings set in the following spring. Within a single year the yield from this region has exceeded in amount the purchase money for the entire Territory of Alaska, and though a large portion of the gold has come from territory within the Canadian lines, American miners for the most part have taken it out. Accurate data with regard to the geography of Alaska it is as yet difficult to obtain. The immediate coastline and the many islands which border it have been mappeui miles following a com- paratively open valley in which there is a good wagon road. Owing to the windings of the stream within the wallH of the valley, the river must be crossed several times, by fords in summer, by ferries in spring when the water is deep. The trail then enters a narrow can- yon with steep, rocky walls, which it follows to Sheep Camp, at timber- line, 44 miles further on. Through the canyon the trail is rougher, but horses have been successfully used for several years in j)ai'kiug to Sheep Camp. Good campingiihu'es are found all along the route from Dyea to Sheep Camp, and at several points refreshments may bo obtained. Sheep C'amp is the last camping-place on the west side of the range, as from there on there is no timber or fuel until Deep Lake, on the other slope, 12 miles distant, is reached. From Sheep Camp to Scales, whore pat^ks are weighed by the Canadian authorities, a distance of 'M miles, the rise is about 1,.S00 feet. The trail is free 14 MAP OF ALASKA, WITH DESCRIPTIVE TEXT. from mud, and traveling is not difficult, though in places the ground is covered with bowlders. From Scales to the summit of the pass the ground rises 1,000 feet in a distance of about half a mile, and masses of broken rock or talus make the climb very difficult, and impossi- ble for pack animals. The building of an aerial or wire tiumway, with buckets carrying 400 pounds of freight, has been contemplated for this portion of the route. From the summit of Chilkoot Pass to Lake Lindeman, a distance of ir>i miles, the trail descends first very steeply to a small lake called Crater Lake, and thence more gradually along the drainageway of a chain of lakes known as Long, Canyon, and Deep lakes, which are connected with one another and finally w ith Lake Lindeman by small streams. Till late in spring the whole of this drainageway is frozen over, and one travels from the summit to Lake Lindeman by sled. On either side of the pass, especially on the south, snow sometimes accumulates to a depth of 50 or 00 feet, form- ing a sort of n6v6 of limited extent. Late in the season, when the draiuagci is open, a ferry sometimes plies on Long Lake, a distance of 4 miles. The rate for psicking from Dyea to Lake Lindeman is 40 cents a pound, and rates are proportional for intermediate points. "Wheu the ice has broken up, Lake Lindeman may be traversed by ferry, a distjince of 4J miles, at $2 a passenger. From the foot of Lake Lindeman there is portage past the rapids to the head of Lake Bennett, where the Dyea and Skiii;\vay trails meet. From the head of Lake Bennett to Dawson, 548 miles, there is a continuous waterway through lakes and rivers, which may be fol- lowed in summer by boat and in winter (m the ice. Long stretches are navigjible by light- draught steamers. Boats may be procured or built at the head of the lake, but in some respecits the most advan- tageous method is to start early enough to travel on the ice Jis far as the foot of Lake Lebarge, where timber for boat-building is abundant, as iu this way the dangerous passage of the White Horse Rapids is avoided. Lake Bennett is 2(5 miles in length, narrow and cauyou-liko iu form, and deep at the lower end. Fitteen miles below the bend, where the southwest arm comes in, strong winds often pre- vail, producing a rough sea that is dangerous for boats, and parties are often storm-bound there IVu- several days. A sluggish stream 2J miles long an miles down Tagish Lake and 5 miles along a river deep enough for ordinary river steamers to IMai'sh or Mud liSike. The Ciinadiitn ciistonis officers and mounted police are stationed on tills river U miles below Tagish Lake. IMarsli Lake is It) miles long and empties into Fiftymile Wiver, whose current aver- ages .i to 4 miles iin hour. About 25 miles down, the river enters Miles Canyon, a chasm aboiit 100 feet wide and five-eighths of a mile I ; r/ 1 uuiLvJu ,ij*»ii ROUTES TO KLONDIKE. 15 long, between perpendicular walls of basalt 80 to 100 feet high. The swift, turbulent current carries a boat through this canyon in about three minutes. For a fair-sized boat, not too heavily loaded, which is kept under steerageway by one or more good oarsmeu and follows the middle of the stream, so as not to be dashed against the steep rocks on either side, the passage is quite practicable. At the foot of the canyon one must keep to the left until the heavy swells are passetl, then turn sharply to the right and land on the east or right bank. A safer course, which is followed by many, is to portage one's load along the right side of the canyon, over a hill about 200 feet high, and run the boat through empty. Three- eighths of a mile below this canyon are rapids ;ibout half a mile long, which, though very rough, are not dangerous. A hall mile below these are the WTiite Horse Eapids, the most dangerous on the whole river. They are about one-third of a mile long and are confined between low basaltic walls. Near their foot the walls close together, forming a chasm only 30 yards wide, while the bed of the stream drops suddenly, so that the river rushes wildly through, leap- ing and foaming in a cataract. Many boats have passed successfully through, but others have been swamped, with loss of outfits ami some- times of life. The safer plan is to portage around the rapids and let the boat down by line. The portage is on the west shore, but on either side a tramway could be coustructeil without great ditliculty. Lake Lebarge, which is (50 miles below the White Hoi-se Rapids, is 81 miles long and easily navigable by steamers. There is abundant good timber at its foot. The river below Lake Lebarge, Jis far Jis Fort Selkirk, is known jis the Lewes, and is also navigable for 160 miles, tlown to the Five Finger liapids. Here a rock of conglomerate rises up from the river bottom, forming several islands and backing up the river a foot or two, so as to produce a strong swell below. Steep cliffs of the same rock on either bank render a portage at this point impracticable. With proper steer.igeway and care, however, an ordi- nary boat may run the rapids safely. The right or cjist 8i5 miles to the mouth of White River, 10 miles further to the mouth of the Stewart, thence li2 miles to Slxtymile River, and 4r> nnles further to Dawson, at the mouth of the Klondike. 16 MAP OF ALASKA, WITH DESCRIPTIVE TEXT. ii: if 11: i 1 i I I ' Ii! Ballon or Chilkat Pass route. — ^This is an overland route following a direct course, more or less independent of waterways, from the head of Chilkat Inlet to Fort Selkirk. It has been used by J. Dal ton, a trader, for some time as a pack-train route and for driving in cattle. But little is definitely known of its geography. It ascends first the Chilkat and Klahoela rivers, crossing the paas in 45 miles at an ele- vation of 3,000 feet and thence descending into the drainage of the Tahkeena River at Lake Arkell. From Lake Arkell the trail is said to pass over an undulating plain, well timbered in the valleys and with grass on the slopes. The distances from the head of the inlet are given as 75 miles to the watershed and 100 miles to Dalton's trading-post. From there to the Pelly the distance is 200 miles, or 300 miles in all to the Pelly, and 350 to 400 to Fort Selkirk. The Stikine route. — By this route one travels by boat from Fort Wrangell 150 miles up the Stikine River to Telegraph Creek, and thence, a little to the west of north, 150 miles to the head of Teslin Lake. The ascent of the Stikine River is tedious and sometimes dangerous, the current being swift and rapids numerous. It is, how- ever, the route that was followed in former days by miners going to the Cassiar district. From Telegraph Creek to Teslin Lake the trail is said to pass through a gently undulating and well-timbered country which presents no obstacles to the building of a railroad. Lake Teslin is said to be about 80 miles long and bounded on both sides by high mountains. From its foot down to the Lewes runs the Teslin (or Hootalinqua) River, which is navigable except for two small rapids, one near its head, the other further down. In its lower course the Teslin spreads out into many channels, occupying a total width of 2 or more miles. This route appears promising, but is as yet only prospective. The Taku route. — This route ascends the Tak\i Inlet and River and crosses directly to Lake Teslin or Aklen, a distance of 185 miles from Juneau. Thence it is identical with the Stikine route. By this route one travels by steamer from Juneau 18 miles up the Taku Inlet to the foot of a large glacier, which is often very dangerous to boats, even at a distance of several miles, by reason of the ice masses that brejik o^" from it ; then by boat (JO miles up the Taku River to the head of p^noe navigation. The portage which follows is for the first 20 miles through the canyon-like valley of an eastern branch, then for 50 miles in broad valleys of the upper Taku, 3,500 to 5,000 feet above sesi-level. For the last 15 miles the route is in the densely wooded valleys of Teslin Lake, among many small ponds. This route is said to be not impracticable for a railroad, and a charter for one has already been granted by the Canadian Government. Its merits, however, have not yet been thoroughly tested. Both tais and the Stikine route have the undoubted advantage of avoiding the dangerous White Horse Rapids. ROUTES TO KLONDIKE. It iga The Edmonton or inland Canadian route. — ^By this route one travels by the Canadian Pacific Eailway to Calgary and thence by branch road to Edmonton, on the Saskatchewan Biver. From Edmonton there are 40 miles of staging to Athabasca Landing, on the Athabasca River, and thence a canoe journey of 1,850 miles down the Athabasca, SIp' e, and Mackenzie rivers to Fort McPherson. The only portage of {a.\y importance is one of 16 miles at Smith Sound, where the Hudson Bay Company has a tramway. This has been the regularly traveled route of the employees of the Hudson Bay Company for nearly a century; aud the canoe trip to Fort McPherson is made in about sixty days. From Fort McPherson one must ascend the Peel River south- eastward, and then travel several hundred miles through an unknown country between Peel River and the Klondike, packing one's outfit. Though advantageous for mining districts along Peel River, this route can hardly be recommended at present to anyone bound for the Klondike region. The Copper River route. — This is only a proposed route, and as yet presents little to recommend it. It would strike inland from near the mouth of the Copper River and follow a general northeasterly course toward the Klondike, thus crossing a great mountain range whose rough topography and many glaciers that fill the valleys and passes render general travel difficult if not impracticable. Orca, the only settlement on the coast nearby, is 50 miles beyond the mouth of Copper River and 700 miles from Sitka. In 1897 it had a population of 22 whites. It is the first post-office west of Sitka. During the hist summer several unsuccessful attempts were made to ascend Copper River. According to C. W. Hayes, there are impassable rapids formed by a moraine below the Miles Glacier, over which the river descends about 100 feet ; there are also rapids lower down at the Childs Glacier, and the broad stretch of river between is rendered dangerous for navigation by floating ice. According to reports of natives, con- firmed by Lieutenant Allen, who crossed over to the Tanana in 1885, the better way is to start inland from Valdes Inlet, on Prince William Sound, and, crossing the Valdes Glacier, strike Copper River 180 miles above its mouth, thus avoiding the gorge and the most danger- ous rapids. The best time to enter the region is in .lannary or Feb- ruary, when the snow filling the crevsisses in the glacier has be;s folded in with it. East of the international boundary the areji in which the granite occurs apparently widens, but its exposures are less continuous, the ovei'lying rocks not yet having been worn away. One granitic axis appears to extend eastward fi'om the Fortymile district through the Klondike region in a nearly east- west direction, which is that of the prevailing strike of th(; f-,edimeuUiry rocks. The Canadian geologists report a second granite axis on the Desise River just below Deji«e Lake, which may belong to the older granites, though they do not make the same distinction tliat .Spurr does between the older gniuites and the later intrusive rocks. Rocks of the various gold bearing series above the granite are reported at the following locnlities : Their ttrst appearance, to one siscending the Yukon from the sea, is near the mouth of the Nowikakat. From here up to the Tanana Jtiver, rocks of the Birch Creek series outcrop frequently along t le river, when not concealed by Tertiary sandstones and conglomerates, and the range of low mountjiins on the north side und parallel to the river is probably formed of these and Fortymile rocks. About .'{ miles above the mouth of the T.iuana, granite is exposed on an island in the Yukon, and 12 miles higher calc4ireouH quartzitic schists of the Fortymile series ai)pe}ir under the i 1 26 ilAP OF ALASKA, WITH DESCRIPTIVE TEXT. I 111!'!' Tertiary conglomerates. From the mouth of the Tanana up to Fort Hamlin, at the lower end of the Yukon Flats, the river runs in a canyon-like channel, known as the Lower Ramparts, cut through a low range of mountjiins which consist principally of the dark greenish and reddish rocks of the Eampart series, except where these are burieiid rock have been observed. In the Birch Creek district, around the headwaters of Birch Creek and southwest of Circle City, the Birch Creek series occupy a broad area; their general strike is east and west, curving at either end to the northward, and the prevailing dip is between 5° and oO° to the south. There is, however, evidence of a northern dip as well, and the Fortymile schists and marbles rest upon them along the trail to Circle City. Marbles, probably beloi ging to the Fortymile series, are also reported in the hills between Birch Creek nnd the Tanana to the south ard. At the crossing of Birch C reek by the trail from Circle City, and along the Yukim River for 'M) or 40 miles above the Yukon Flats, rocks with the characteristic dark (coloring of the Rampart series are exposed. From these up to the mouth of INIission Creek rocks of the Tahkandit, jNIission Creek, and Kenai series occnjjy the banks of the river. On iMIssicm Crock itself only these later formations are found, but the gold in the gravels is supposed to come from tlie conghmier- ates ('^cement rock") of the IMission Creek series, wiiich contain peb- bles of the older rocks. On American Creek, tlu! main branch of IMission Creek which conu'S in from the south, the (hirk roc^ks, shales, limestones, and luH'aceous beds wliich tbrm the bed-rock are supposed to belong to the l{anii)arl seri«'s, which also occur along the Yukon River fnuu 5 to 10 miles above Missioi; (U-eek to vvithin 25 miles of the nu)uth of 1^'ortymile Creek. Above (his to sonio distance above Fortymile C5reek the river runs in beds of the Mission (!reek series. It is in the Fortymile district and the adjoining mining district on tributaries of Sixtymile Creek thai lh(> relations of (lie dillerent gold- bearing series are IteM seen. Here i\\mv. is an east west axis or back- bone running ])arallel to the upper part of Fortymile Creek and along the diviile between it ami Hix(ymile Creek, wi(h quartzite-schists of CANADIAN TERRITORY. 27 the Birch Creek series resting immediately on it both to the north and to the south. Above these on either side are the marbles and alter- nating schists of the Fortymile series. Fortymile Creek below the forks runs for a considerable part of its course along the junction between these two series, on the northern flank of the anticline. Dikes of various eruptive rocks, including intrusive granite, are very abun- dant, especially on the South Fork. On the upper part of this fork are green tuffs and slates of the Kampart series, overlain unconform- ably by conglomerates, sandstones, and coaly shales of the Mission Creek series. Both the South Fork and Svxtymile Creek are sup- posed to head in a backbone of granite around Sixtymile Butte, which is surrounded by quartzite-schists of the Birch Creek series. These regions lie partly in American, partly in Canadian territory. CANADIAN TERRITORY. The Canadian area has not been studied by American geologists, except in wayside observation along su(!h routes of travel as necessarily lay through it. The Canadian geologists, on the other hand, did not in their earlier and published observations recognize any subdivisions in the older rocks such Jis have been made by Spurr. Hence it is not possible to attempt even a proximate outline of the Canadian gold- bearing rock formations. General geological data and local discoveries of gold-bearing gravels indicate that the gold-bearing areji is very large, and may be roughly defined as reaching from Dease River to the boundary, with a width ot 200 to MOO miles or more. The recent enormously rich dis(!o\eries have, however, been (confined to a more limited area around the Klondike and Stewart River districts, on er which it has been jiossible to extend, with a reasonable degree of probability, the colors indicated on the map for adjoining American areas. Thus it is assumed that the east-west uplift of fundamental granite and overlying rocks extends eastward into the Klimdike dis- trict, and that a se(!on(l uplift in a south ejisterly direction extends from upper l^'ortymile ('reek toward the valley of Stewart River. Spurr noted outcrops of the schistose quartzilcs of the Birch Creek series for a large part of the distance from the mouth of Fortymile ('reek up to the Junction of (he I'elly and the Lewes at Fort Sellvirk; also granites at various points, in souuj cases schistose like the funda- mental granite, in others fresh and massive like intrusive granite. There were also occasional belts of marble belonging to the Fortymile scries, notal)ly one 5 or (i miles abov«! the mouth of Sixtymile ('reek, not far IVont tlnit of Slowari IJiver. These observations atVord a rough section across liic belt (»f crystalline schists mentioned by the Canadian geologists as stretching eastward and southeastward along the upper Pelly and adjoining streams and acrovss to the Frances River. Along the eastern edge of the crystalline belt they also recognized rocks of - ' I 28 MAP OB" ALASKA, WITH DESCRIPTIVE TEXT. a general greenish color, made np largely of altered volcanic rocks, which would answer to the description of the Rampart series. Similar rocks were also noted at various points on the Lewes above its junction with the Pelly, notably in the Seminow Hills near the Big Salmon Eivei , which may represent the development of the Rampart series on the south flanks of the crystalline belt. DETRITAL OR PLACER DEPOSITS. FOSSIL PLACERS. Intermediate between detrital materials of the present surface and original deposits in rock-in-place are conglomerate or cement beds, derivent. 32 MAP OF ALASKA, WITH DESCRIPTIVE lEXT. mi .,; 1,1 Gulch gravels. — Coarse gold can not, under ordinary circumstances, be carried very far by running water ; hence it is in the gulches that the rich deposits of coarse gold are ordinarily found, and in the side gulches that it is generally the coarsest, as in them the gravel is nearest its source. It is not always actually running water that has concentrated the gold; the metal is so much heavier than rock material that a relatively slight disturbance of loose material, if continued long enough, will result in settling most of the large particles at or near the bed-rocks. Still, that running water is the most important factor in the concentration of gold is shown by the fact that this concen- tration is greatly dependent on the nature of the bed-rock ; where this presents a rough, ragged surface, especially where ridge-like protru- sions run across the stream, like the riffles in a sluice box, the gold is more readily caught aud the gravels resting in it are much richer than where the surface is smooth, even, and without many cracks. Thus the experienced miner knows that where there is a narrow dike of harder roek, or, still better, a series of hard schistose rocks standing on edge that cross the gulch in which he is working, he is liable to find the richest concentration of gold, and that in the latter case it may even settle down into the cracks of the bed-rock for several feet. The lowest channel does not necessarily correspond with that of the present stream, since the latter, as already noted, is frequently chang- ing its course within the material accumulated in the long years during which it hjis been flowing, and it may have been pushed to one side or the other of the valley by landslides. The actual pay dirt is generally confined within comparatively few feet of the bed-rock. Sometimes the miner finds what he calls a false bed-rock, which is generally a clayey seam that marks some special stage in the history of the stream. The amount or depth of gravel in the bottom of a gulch or valley is depeudeut on its size aud shape, and the experienced eye can estimate approximately what it is by mentally carryiug down the outlines of the rock surface on either side of the valley to a meeting under the geutler-sloj)ing valley bottom . It is also, naturally, much thinner near the head of a gulch, and in tliis region, where these heads are frequently occupied by glaciers or bodies of perennial ice and snow, they generally have a rounded, amphitheater-like shape, the breaking down of the rock occurring mainly at its contact with the ice. In the great diurnal changes oi' temperature of the short summer months of this region the water seeping into rock cracks by day is frozen at night, and by its expansion pries off' fragments from the cHUh. The material thus loosened gradually slips down; but, as a rule, not until it hjis been moved for a considerable distance, ordi- narily some miles down the valley, is the gold thoroughly settled to the bottom along the bed-rock surface. The general character of the gravel, aud of the gold itself in the DETRITAL OR PLACER DEPOSITS. 88 gulches that have been studied, such as those in the Fortj^mile and Birch Creek districts, shows that the gravels have not been carried very far. The rock fragments are not completely rounded ; they are generally rather angular, and often quite tlil. The gold also is not completely rounded. CHARACTERISTICS AND iJISTRIBUTION OF KNOWN PLACERS. The extraordinarily rich placer deposits of the gulches tributary to the Klondike liiver above Dawson, and of similar gulches of the nearby Indian Creek and Stewart River, have been so recently opened that no detailed geological description of these localities has yet been received. In his report, however, Spurr had shown that the strike of the gold-bearing rocks in the Fortymile district, and the exposures observed along the Yukon, indicated that their gold must have been derived from the same gold-bearing formations that had furnished the richest placers in the districts visited by him. A brief statement of the prominent characteristics of these districts as given by him will therefore probably be of value to the prospector. Geologj' can give only general indications and point out where gold may be found. The actual location of rich concentrations must be determined by the miner himself. The hills surrounding the gulches of the Little ^Mynook and Hunter creeks, on the Lower Yukon, are formed of rocks of the IJampart series. The bed-rocks are of diabase, tutl's, impure shales, and quartz- ites, and in the bottoms of the gulches there is from 10 to 20 feet of gravel. The gravel consists in part of angular fragments of rocks that form the walls of the gulch, in part of waterworn pebbles of Birch Creek schist, schistose granite, and other rocks. The gold is gen- erally in rounded, beau-shaped grains and nuggets, and less frequently in unworn particles. This points to a two-fold origin of the gold, as derived in part from the rocks immediately about and in part from distant and older rocks, which may have been worn down, possibly along an old seashore, into terrace gravels, and then by subsequent erosion brought into the ])rcseiit stream l)eds. Further exploration in the hills to the south may disclose the true source of these pebbles and of the gold that accompanies them. On American ('reek, in the Mission Creek district, the gold-bearing placers are also derivetl from rocks of the Rampart series — quartzitic schists, serpentines, and chloritic rocks — and the gold is said l)y Spurr to have been derived mainly from the schistose zones in tl»e bed-rock. The richest gravels have been found in the Birch Creek and Forty- mile districts. In the entire Birch Creek district, which lies south of Circle City, and on Miller, Glacier, Poker, and Davis creeks of the Fortymile district, near the international boundary, the bed-rocks are always the quart/ite-schists of the Birch Creek series, containing veins • "HV V »l7.f '7., w-t; V; 34 MAP OF ALASKA, WITH DESCRIPTIVE TEXT. m ,S!,i of quartz. The gravels rest, as a rule, directly on the schist, though in some cases, as on Harrison and Eagle creeks in the Birch Creek district, there is clay beneath the gravels, and the gold as a rule does not extend into the bed-rock but occurs chiefly at the top of the clay. Generally, however, the schist is rotted and reddeuetl from oxidation for a few inches to several feet below the surface, and in this part the gold has settled into the ci-acks and joints. The pay gravels lie mostly next the bed-rock, in an average thickness of perhai)8 2 feet, though sometimes up to 10 feet, while the overlying gravels average 8 or 10 feet, with a maximum of 25 feet. In the gravels the schist is in quite large, flat fragments, and the quartz is in bowldvers of varying size. The schist frr^gments lie flat, and are mixed with sand, showing that the sorting action of running water hsis not been carried far. In the concentrates from the sluice boxes the heavier minerals associated with the gold — galena, magnetite, limonite, hornblende, and garnet — are in each case such as are found in the neighboring schists, and the nuggets of gold often have pieces of quartz still adhering to them. All these facts are evidence that the gold is derived from rocks in the vicinity, and is not brought from a great distance, perhaps by glaciers, as some erroneously suppose. The rocks of the Fortymile series in the Fortymile district, as already stated, form the west bank of Fortymile Creek, and south of the South Fork cross the divide between Franklin Gulch and Napoleon Creek, where they are overlain by green slates of the Rampart series, which in turn are overlain by conglomerates of the Mission Creek series. In Fninklin Creek the bed-rocks are marbles interbedded Avith mica- and hornblende-schists ; the gravel contains fragments of marble, quartzite, micui-schists, and vein quartz. At one point a quartz vein is found in the bed-rock, and below it native silver has been found in the gravels, which apparently came from this vein. It is the schistose rocks that mostly carry the gold, as the marbles do not show much evidence of veins. In this gulch are two levels ; the higher one, at the head of the gulch, had not been worked, while the pay gold had been found mainly at the lower level, near the mouth of the gluch. t'hicken Creek, so called because its gold occurs in grains the size of chicken feed, drains a wide area toward the Ketchumstock Hills to the southwest, and the actual source of the gold is less readily deflned. The gravel contains fragments of granite, quartzite, schist, and marble. On Napoleon Creek conglomerate forms the bed-rock near the mouth. The gravels contain fragments of quartzite, vein quartz, hornblende-granite, and various eruptive rocks, and the source of the gold is assumed to be the conglomerate, which is made up of frag- ments of the older rocks, for the rocks higher up the gulch above the conglomerates have not been found to carry much gold. -■tlJWU?JiA:Di»5f<.l73.'^-T EXTENT OF GOLD-BEAKINO DEPOSITS. 86 The most trustworthy reports from the Klondike region indicate that the exceptionally rich placer gravels thus far found occur in side valleys entering the main Klondike Valley from the south, such as lionanza, Eldorado, and Hunker creeks, and in some gulches across the divide tributary to Indian or Stewart rivers. No gold in paying quantities had been found on the Klondike itself. The placer deposit generally consists of 10 to 15 feet of frozen muck and decayed vegeta- tion at the surface, then a gravel bed that rarely pays; below that a clay selvage, under which is pay dirt from 1 to 5 feet in thickness resting on the upturned edges of the schist, from which it is separated by a clay selvage. The pay streak or bottom of the old channel is usually very regular and straight, not following the bends of the present stream. It is said to average GO cents to the pan, and may yield $1 to $.'{. Only very exceptionally rich gravel can be worked at all under present conditions. PROBABLE EXTENT OF GOLD-BEARING DEPOSITS. In a new country gold is first sought in the stream gravels, and thence traced up to its source. Very fine gold may be carried long distances by river waters ; hence it is only when it becomes relatively coarse, or at any rate carries coarse particles, that the source may be considered necessarily near at hand. Fine gold is found in almost all the rivers of Alaska; even the silts of the Yukon yield it in places. Gold has been found along the whole length of the Lewes, the Teslin, the IJig Salmon, the Pelly, the Stewart, and the Selwyn, and on the Yukon River almost continuously from the junction of thr Lewes and Pelly downward. Still further east, Frances and Dease rivers, the main branches of Liard River, which flows into the Mackenzie, carry gold. In the Cassiar district, on the Dease River, gold was discovered as early as 1861. The district was actively worked as a placer camp from 187;^ to 1887, during which time it yielded about five million dollars' worth of gold dust. These upper regions are distant about 1,000 miles in a straight line from the known outcrops of gold-bearing rocks in the Rampart Mountains on the Lower Yukon, and are within areas either in which exposures of the gold-bearing rocks as defined above are actually known to exist or in which the similar lithological character of rocks described renders it probable that in some part of the area they may be exposed. There is also some evidence of the extension of rocks of the gold- bearing series to the northwest of the Lower Yukon, though it is as yet impossible to determine whether the primitive gold-bearing rocks of the Birch Creek and Fortyraile series there come to the surface, or whether it is simply the fossil placiers or gold-bearing conglomerates of later fornuitious, where made up of fragments of these older rocks, that have furnished the gold of modern streams. 36 MAP OF ALASKA, WITH DESCRIPTIVE TEXT. :f!i I 'I' J! I tti . in m In this re{?iou sold has been found extensively along the Koyukuk, and most abundantly, as already mentioned, where the valley cuts through conglomerates, supposed to belong to the Kenai series. This is at the forks, about 300 miles above the mouth, below which the country is low and swampy. Above the forks the mountains close in and the sides of the valleys become precipitous. The gold in the bars is 8ai into chip- like pieces. The geological formation containing the coal and leaf- bearing jhales is called the Kenai formation, and is usually covered by beds of sandstone containing fossil oysters and other shells belong- ing to the Miocene or middle Tertiary. Many coal seams have been partially explored, rnd a much larger number have been reported but not examined by experts. Of the former the following beds promise to have some commercial import- ance, though none has been thoroughly exploied in a scientific manner. Admiralty Island coal field. — The broken mass of land named Admiralty Island is penetrated by a complex system of waterways known as Kootznahoo Inlet. The land is comparatively low, and in places on the shores coal seams and leaf- bearing shales crop out, of which a number have been prospected. Many of the beds are broken up by faults and fractures, but these conditions are less conspicuous in the eastern part of the area surrounding the inlet. The most promising deposits are at the extreme east, at the head of a body of water called Davis Creek, about 10 miles by water from the entrance of the inlet. About 100 tons of coal have been taken out here by the proprietor of the mine, who has found a ready sale for it. It is not a coking coal. The locality is situated about 40 miles northeast from Sitka, near the Killisnoo village. Cook Inlet or Kenai coalfield. — This is the largest and most imiwrtant coal field known in Alaska. It is situated on the Kenai Peninsula, forming the eastern shore of Cook Inlet north of Kachemak Bay, where the coal seams are exposed in high bluffs rising to nearly 2,000 feet above the sea. From these biutt's the coal extends northward, with gentle undulations, and finally dips below the sea-level near Cape Kussilof, covering an urea about 70 miles long and .SO miles wide. At Kachemak Bay, where the best outcrops ami the only good harbor are found, there are six or seven beds, one above another, the thickest being 4 feet thick, and the best coal coming from the lowest beds. A good deal of prospwting has been done here and several shiploads of coal have been taken out. The (\>ok Inlet coals have about the average amount of moisture, less than the avtunge amount of ash, reniarkably little sulphur, and nu)re than the average amount of volatile com- bustible matter. "When all the conditions arc taken iu.'o oc'^urt, \\v- ■■i wmmm COAL AND LIGNITE. 41 Cook Inlet coal field is by far the most promising commercially of all Alaskan coal deposits. Amalik Harbor coal seam. — This is situated on the south side of Alaska Peninsula, in longitude 154° 30' W. The seam is small at the outcrop and has not been explored, but the coal is of very excellent quality, coking well, and larger seams may exist in the vicinity. IJnga Island coal seams. — ^These are on the shores of Zacharefskaia Bay, on the north side of the islana of TJnga, Shumagin group, and have been worked more or less since 1865. The coi.l is of poor quality and contains an excessive amount of sulphur, but has been utilized to some extent for local puri>os'«. Chignik Bay ''oal seam. — This is situated on a river flowing into Chignik Bay, on the south side of Alaska Peninsula, in about longi- tude 158° 33' W. The coal is of good quality, and several hundred tons have been mined for use in the local salmon cannery, where it is reported to give satisfaction. ^■rendeen Bay coal field. — This is situated on the north side of I .' ".a Peninsula, on a i>oint which separ-ttes Herendeen and Moller buys. The field is about 4 miles square, but there are several vol- cajiOAs in the vicinity and the rocks are more or less faulted. Some handrecis of tons were taken out from a mine near the head of Herendeen Bay, but the mine is no longer in operation. Cape Llsburne coalfield. — This deposit, before alluded t«, is situated on the Arctic coast, extending in a general way from a point a 'ew miles eastward from Cai)e Lisburne to Cape Beaufort, a distance of over 25 miles. Its inland extension is unknown, and whether the coal which occurs on the same coast further north is of the same age or not is likewise unknown. The Cape Lisburne coal has been used extensively '»y the steam whaleshipt , but no reguhir mining operations have been ■ 'urtaken. Coal ( tj 1^ * ;' V of the Kenai formation which usually contain more or less I Ml' i 'f been reported from the following localities, but the character, e\v' it. iiud availability of such deposits are unknown or problematical. AliKXANDKR ARCHIPKLAGC St. John Baptist Bay, about 16 miles in a nortiiV.cv.ierly dirwtion from Sitka. Surprise Harbor, near Point Gardner. This is at the southern extrenui of the ^mimlty group of islands, on Frederick Sound. Po): <' iden. This bay penetrates Kuiu Island from the northesust. The cok; i the east side of the bay, 7 miles from the entrance. Whale Bay, Bara no/ Island. This is about 23 miUw soiitluuist from Sitka. M^cst coast of Kuiu Island. Coal in latitude 56° 25'. 42 MAP OF ALASKA, WITH DESCRIPTIVE TEXT. Il^i TAndenherg Peninmila. Coal or lignite on the northern shore of Kuprejinof Island. Ohwhagof Maud, at the southeastern extremity, on Chatham Strait. Hood Bay, on the opposite shore of i hatham Strait from the last lociility. Prince of Wales Island, near Kasahan Bay. Seymour Canal, Admiralty Island, near its western part. COAST BETWEEN CAPE SPENCER AND COOK INLET. lAtuya Bay. Exact locality not known. Ynkutat Bay. On the northeastern shore, near Disenchantment Bay. Port Graham. At the southeast entrance to Cook Inlet. Copper River delta. Petroleum in considerable quantity, as well as lignite, is reported hei» ' ■* ALASKA PENl... A AND ALEUTIAN ISLANDS. Cape Doufflas, at west point of entrance of Cook Inlet. Katmni. On the portage across the peninsula from this bay both coal and petroleum are reported. Umnuk Bay, Kadiak. Also on Uganuk Island, in the Bay. Red River, Kadiak. Sitki7iak Inland. Southwest of Kadiak. Yanlarnic Bay. South side of Alaska Peninsula, in longitude 157° 10' W. Cold Bay. South side of the peninsula, in longitude 155° 25' W. Coal Cape. South side of the i^eninsula, in longitude 159° W.; also: Coal Bay and Porfaye Bey, near by. Parlof Bay. West shore, near Pavlof Mountain. Akuu Inland . Anther Lake, Cnalaska. Near the center of the iHlaud. Unmak Island. Northwestern extreuie. Sandy Bay, Atka Island. Kirilof Bay, Aniehitka Island. COAST AND ISLANDS OF BKRIN« SKA. l*oint Vaneourer. [J^nalaklik Rirer, Norton Sound. Topa n ika , No rton Sound. llukak River Valley, Norton Sound. LOWER TUKON RIVKR VALLEY. Andrea/ski Post. Kallaff villaye. Nvlato. Seven miles below the post, on right bank of the Yukon ; iilso iil)ovc llu' ])(«< oil the same bank, for several uiiles. Melozik mouth of There a Canadian Kowak J is a coal fi Waimor\ the inlet. In concl made give of 0.927, > 1.351, the Bay at 1.1 From th following c Hess Cre of Hess (a] are exposec vertical. ' limestones, which is 2 coaly shak tains .ipeck and 7 to 8 Coal Cret miles beloM diau territ< about 12 m been taken rather light specks. It carbon thai (iharacter. Other loeu onteriug tlu also on Cha Beds h- <'oal seams, reported fr( Uiver, nota Kiver, and COAL AND LIGNITE. 43 Melozikdkat. On the left bank, 20 miles below the settlement at the mouth of the Melozikakat. There are other localities reported further up the Canadian territory. river, ehieHy in ARCTIC COAST AND RIVERS. Koicak River, Kohehue Sound. Seventy-five miles above the mouth is a coal field 30 miles wide. Waimcright Inlet, Arctic Ocean. On the banks of a river enterinj; the inlet. In conclusion it may Ije said that the tests of Alaskan coals so far made give a fuel value for the best Alaskan lignite from Cook Inlet of 0.927, when the Wellington coal of British Columbia is rate^»u:jii.k^ .iff^- \ '15 ,i*4>»««'"'i \ rni: (iou) and TOGETHER WITH THE PRINCIP, \^ 'i* Scalf I ::tF THK (NTKKloK r. S <.H()LO(;l('AI, SIRNKV CHARLES D. WAL.COTT. DIRECTOR ■< / lOl.l) AND COAL l-IKI.DS OF ALASKA '^i ^ WITH THE PRINCIPAL STEAMER ROUTES AND TRAILS Scal<- - l:;t<;<■ " i\»*, rT^