Bonanza Peak is a 6,983-foot (2,128 meter) mountain summit located in the

Wrangell Mountains The Wrangell Mountains are a high mountain range of eastern Alaska in the United States. Much of the range is included in Wrangell-Saint Elias National Park and Preserve. The Wrangell Mountains are almost entirely volcanic in origin, and they i ...

, in the

U.S. state In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sover ...

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

. The peak was notable for its abundance of copper deposits which were mined from 1909 through 1938. The peak is situated in Wrangell-St. Elias National Park and Preserve, immediately northeast of Kennecott, northeast of McCarthy, north of Porphyry Mountain, and southeast of Donoho Peak. The confluence of the Kennicott and Root Glaciers lies below the mountain's west slope. Precipitation runoff from the mountain drains into tributaries of the

Nizina River Nizina River is the largest tributary of the Chitina River in the U.S. state of Alaska. It is located in the Wrangell–St. Elias National Park and Preserve. Geography The stream heads in Nizina Glacier, flows southward about to a point near the ...

, which in turn is part of the

Copper River Copper River may refer to several places: *Copper River (Alaska), in the United States * Copper River (British Columbia), a tributary of the Skeena River The Skeena River is the second-longest river entirely within British Columbia, Canada (afte ...

drainage basin. The mountain's local name was reported in 1914 by the U.S. Geological Survey. On a clear day the summit of Bonanza Peak offers views of Sourdough Peak,

Mount Blackburn Mount Blackburn is the highest peak in the Wrangell Mountains of Alaska in the United States. It is the fifth-highest peak in the United States and the twelfth-highest peak in North America. The mountain is an old, eroded shield volcano, the se ...

, and

Fireweed Mountain Fireweed Mountain is a prominent 6,956-foot (2,120 meter) mountain summit located in the Wrangell Mountains, in the U.S. state of Alaska. The peak is situated in Wrangell-St. Elias National Park and Preserve, immediately west of the terminus of t ...

History

Bonanza Peak hosted five mines: Bonanza, Jumbo, Mother Lode, Erie, and Glacier. The Bonanza ore body was discovered August 1900 by

prospector Prospector may refer to: Space exploration * Prospector (spacecraft), a planned lunar probe, canceled in 1962 * '' Lunar Prospector'', a NASA spacecraft Trains * Prospector (train), a passenger train operated by the Denver & Rio Grande Western ...

s "Tarantula" Jack Smith and Clarence L. Warner. Bonanza Mine was located on a ridge south of the summit, and was in the early 1900s, confirmed by

Stephen Birch Stephen Birch (1873–1950) was the President of the Kennecott Copper Company. Early life Birch was born in New York City on March 24, 1873. He was the second son out of six children. His father was a Union Army sergeant who died when Steph ...

as the richest known concentration of copper in the world. Glacier Mine, which is really an ore extension of the Bonanza, was an open-pit mine and was only mined during the summer. Jumbo Mine was in the west

cirque A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landform ...

below the summit. The Mother Lode mine was located in a cirque on the east side of the summit. The Erie mine was perched on the northwest slope above the Root Glacier. The Bonanza, Jumbo, Mother Lode and Erie mines were connected by tunnels. From 1909 until 1938, the mines produced over 4.6 million tons of ore containing 1.183 billion pounds of copper mainly from the Bonanza, Jumbo and Mother Lode, as well as several million ounces of silver. The Kennecott operations reported

gross revenue In accounting, revenue is the total amount of income generated by the sale of goods and services related to the primary operations of the business. Commercial revenue may also be referred to as sales or as turnover. Some companies receive revenue ...

s above $200 million and a

net profit In business and accounting, net income (also total comprehensive income, net earnings, net profit, bottom line, sales profit, or credit sales) is an entity's income minus cost of goods sold, expenses, depreciation and amortization, interest, a ...

greater than $100 million. Present-day visitors may hike to the abandoned Bonanza, Jumbo, and Erie mines, all of which are strenuous full-day hikes, with Erie Mine being a somewhat terrifying scramble along cliffs overlooking the Stairway Icefall.

Geology

Bonanza Peak is part of the

Wrangellia Terrane The Wrangellia Terrane (named for the Wrangell Mountains, Alaska) is a crustal fragment (terrane) extending from the south-central part of Alaska and along the Coast of British Columbia in Canada. Some geologists contend that Wrangellia extends ...

. Copper deposits are found at the

disconformity An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval o ...

between the Upper

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

Chitistone

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

and underlying

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

Nikolai greenstone.Geologic Studies in Alaska bu the U.S. Geological Survey, 1995. Robert P. Eppinger,Stephen J. Sutley, and John B. McHugh. Page 19-22. Copper is found as

polymetallic replacement deposit A polymetallic replacement deposit, also known as carbonate replacement deposit or high-temperature carbonate-hosted Ag-Pb-Zn deposit,Megaw, P.K.M., Ruiz, J., and Titley, S.R., 1988, High-Temperature, Carbonate-Hosted Ag-Pb-Zn(Cu) Deposits of Nor ...

s in the

fault plane In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

fractures Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displa ...

and

joints A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

. Minerals include

chalcocite Chalcocite (), copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system. The ...

bornite Bornite, also known as peacock ore, is a sulfide mineral with chemical composition Cu5 Fe S4 that crystallizes in the orthorhombic system (pseudo-cubic). Appearance Bornite has a brown to copper-red color on fresh surfaces that tarnishes to v ...

and

chalcopyrite Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mo ...

, with associated

malachite Malachite is a copper carbonate hydroxide mineral, with the formula Cu2CO3(OH)2. This opaque, green-banded mineral crystallizes in the monoclinic crystal system, and most often forms botryoidal, fibrous, or stalagmitic masses, in fractures ...

azurite Azurite is a soft, deep-blue copper mineral produced by weathering of copper ore deposits. During the early 19th century, it was also known as chessylite, after the Type locality (geology), type locality at Chessy, Rhône, Chessy-les-Mines near ...

, and

cuprite Cuprite is an oxide mineral composed of copper(I) oxide Cu2O, and is a minor ore of copper. Its dark crystals with red internal reflections are in the isometric system hexoctahedral class, appearing as cubic, octahedral, or dodecahedral forms, o ...

Native copper Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native coppe ...

can also be found in the greenstone. The deposits were mined for their spectacularly high-grade copper ore which exceeded 70 percent.

Climate

Based on the

Köppen climate classification The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

, Bonanza Peak is located in a

subarctic climate The subarctic climate (also called subpolar climate, or boreal climate) is a climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, ge ...

zone with long, cold, snowy winters, and cool summers. Weather systems coming off the

Gulf of Alaska The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, ...

are forced upwards by the Wrangell Mountains (

orographic lift Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...

), causing heavy precipitation in the form of rainfall and snowfall. Temperatures can drop below −20 °C with wind chill factors below −30 °C. The months May through June offer the most favorable weather for viewing and climbing.

Gallery

File:Kennecott Mill site and Bonanza Peak.jpg, Kennecott Mill site with Bonanza Peak File:Bonanza Peak and Kennecott.jpg, Bonanza Peak and Kennecott File:Sunset Panoramic View from West Side Root Glacier Campsite.jpg, West aspect of Bonanza across Root Glacier File:The remains of the Jumbo Mine.jpg, Jumbo Mine ruins in bullseye, summit in upper right. File:Erie Mine above the Root Glacier.jpg, Erie Mine ruins in bullseye at contact line of limestone overlaying greenstone File:Erie Mine.jpg, Erie Mine ruins File:Old route to the Bonanza Mine.jpg, Old route to the Bonanza Mine

References

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External links