.es { A, Economic Geology, 25 Professional Paper No, 15 8en B, Descriptive Geology, 30 DEPARTMENT OF THE INTERIOR UNITED Sl'ATES GEOLOGICAL SURVEY CHARLES D. WALCOTT, DIRECTOR THE MINERAL RESOURCES OF THE MOUNT. WRANGE.LL DISTRICT, ALASKA BY WALTER C. .MENDENHALL AND FRAJ'!K C. SCHRADER WASHINGTON GOVERNMENT PRINTING OFFICE 1903 4 CONTENTS. / Copper-Continued. l'age. Southern area-Continued. Copper occurrences-Continued. Description of properties-Continued. Deposits in the Chitina drainage basin.................................... 27 Strelna Creek deposits.. 27 Kuskulana River occurrences......................................... 27 Bonanza mine... 27 Old Independent vein.......... 28 Nikolai mine . 28 Other occurrences . • . 29 Northern area........................................................................ 30 General statement ......................................................... ,...... 30. Routes and trails................................................................. 30 Copper occurrencee . 32 Upper Copper River region. • . • . 32 Upper Tanana or Nabesna and Chisana region ............ ·.·····.............. 33 Geologic sketch.................. 33 Monte Cristo diorite...... 34 Nabesna limestone.................................................... 34 Character and occurrence..... 34 Age ...... -------~---·············································· 35 Diabasic series . 35 Character and occurrence...... 35 . Relations and age . 36 Mesozoic series ......................................·.......... 36 Occurrence and character . .. 36 Relations . 36 Age.............................................................. 37 Occurrence of copper ............................· . 37 On the upper Nabesna................................................ 37 On Camp Creek...... 39 On Cooper Creek. 39 On the Chisana . • . 39 On \Vhite River .................................. , ................. :. 40 Upper White River.............................................. 40 :Middle White River...... 41 Economic considerations ........................................................... -.. 42 Gold ................................................... - .. - ........ -- .......... -- .... - --. 43 Nabesna River region ....................................................... ·.......... 43 Chisana River region................................................................. 45 \Vhite River region................................................................... 45 Mentasta Mountain region ............................... -.- . 46 Routes and trails . 46 Geologic sketch ..................................... -- - -. - - .... -. - ...... - . 46 Gold occurrences ....· ................ ~ ..... ------.-------.. ---.-.. - .. -- ........ -.. 47 CONTENTS. 5 Gold-Continued. Page. Chistochina gold field . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. • . 48 Location ......................................... ~........... .. .. .. .. .. .. 48 Geography and drainage ............................... ".......................... 48 History.......................................................................... 49 Trails............................................................................ 49 Mail an~. telegraph .facilities . • . 50 Geologic sketch ··--------~-----. ........... ...... .................. ........ ...... 51 Gold occurrences . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 52 Output....................................................................... 52 Miller Gulch................................................................. 52 Slate Creek................................................................... 53 Big Four claims ................·.............................................. 54 Chesna River. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 55 Upper Chesna-Ruby Gulch . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 55 Lower Chesna............ .. .. .. .. .. .. .. .. .. .. .. .. .. 56 Origin of the gold.... 57 Influence of glaciation ............................................................ · 58 Economic conditions.............................. .. .. .. .. .. .. .. 58 Delta River district................................................................... 59 Nizina gold field .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 59 Bremner district...................................................................... 62 Tiekel and Tonsina districts . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 62 Fall Creek....................................................................... 62 Quartz Creek..................................................................... 63 Other minerals........................................................................... 63 Silver................................................................................. 63 Platinum............................................................................. 63 Tin ..................................................................... ,............ 64 Mercury. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 65 Osmiridium . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 65 Iron ..... 0 ........................................................... ................ 65 Nabesna region..... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 65 Gakona-Chistochina region........................................................ 66 Coal................................................................................. 66 Chistochina River................................................................ 66 Gakona River .. ~................................................................. 67 White River . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 67 Tazlina River . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 67 Chitistone River.... .. .. .. .. .. .. .. .. .. .. .. .. 67 Cheshnina River . .. .. .. .. .. .. .. • . .. .. .. .. .. .. .. .. .. .. 68 ILLUSTRATIONS. • Page. PLATE I . A, Mount Wrangell; B, Nadina River bars, Mount Drum in background .. Frontispiece. II. Outline, 1nap of Alaska.......................................................... 10 III. Map of the Mount Wrangell district . • . • • . • . • . • . • • • . •• . • . 14 IV. Map of the southern copper area .......................... _............. _... _... 16 V. A, Warner copper prospect and tunnel, near mouth of Rock Creek; B, Valley of Lime Creek, a tributary of Rock Creek ........ _.•.. _.................. _. • . 20 VI. A, View of Nikolai mine across upper Nikolai Creek; B, View of Bonanza mine from Horseshoe trail ••...•••....•...••..•.. _.•.....•........... _..... _. • . 28 VII. A, Monte Cristo diorite intruded by diabase; B, Nabesna limestone intruded by diabasic series on Nabesna River .... _...........••............... _......... _.. 32 VIII. A, Monte Cristo diorite on Monte Cristo Creek; B, Venation and disintegration in Monte Cristo. 'diorite .•.•..• __ .•...•••..•• ~ .................... _...........•.. _ 44 IX. Map of Chistochina gold tield ...•...••.....•.••.•••..•. ~ •... _. 48 X. A, View of Miller Gulch; B, View of upper Ruby Gulch, showing lower end of Jackpot claim .....••...•.•.... _.. • . • .. • . • . • . 52 FIG. 1. Protile and S!"ction from Copper Creek to Elliott Creek........................... 22 2. Map of the Elliott Creek copper claims ....••........••......•.....•.. _........... 23 3. Map of the region adjacent to the upper Nabesna River. ....... __ ................ 38 4. Sketch map showing location of Kletsan Creek copper deposits . • . • . 41 5. Sketch map of Nizina gold tield... ••. •• • • . • • • • • • • • •• . • . •• . • ••••• •• • . • • . • . .. .. 60 7 • • • THE MINERAL RESOURCES OF THE ~IOUNT WRANGELL DISTRICT, ALASKA. By "\\T ALTER C. MBNDJ<JNHAI,L and FRANK C. SCJCRADER. IN'l'RODU U'l'ION. The Tenth Census, taken in 1880, gives the number of white inhabitants of the Territory of Alaska n.s 430. In the decade from 1880 to 1890 this number had increased to 4,298, and in the following decade, that between 18!)0 and 1900, a further increase to 30,493 is reeorded. The Director of the Mint in his report for 1891 gives the value of the yield of the Territory in precious metals as $772,U)7. By 1900 these figures were increa:sed to $8,:365,772. These statistics of the growth in population and in mineral output of Alaska serve as an index to the general increase in the importance and· commercial value of the Tetritory as an integral part of the domain of the United States. The larger ·part of th'is growth began with the discovery, late in the autumn. of 1896, of the placer deposits of Klondike River in Canadian Yukon territory. Soon rdter this discovery there was a great influx of prospector:-, HJiners, and , bm;iness men to all parts of Alaska, but partieularly to the regions tributary to the Yukon, and with this increase in population came a proportional incr.ease in transportation facilities and business interests. An important part of the general movement toward Ahtska during this period was directed toward Copper River, the immigration there first reaching con;.;ider­ able proportions in the spring of 1898. Previous to this date something had been learned of the geography and less of the geology of the Copper River Valley through a number of .explorations, usually made under the auspices of the War Department. Lieutenant Abercrombie" reached Mile;.; Glacier in 1884 in an attempt to ascend the river, and Lieutenant Allen b in 1885 explored the main valley