To Move A Mountain
Railroads and Mining in Utah's Bingham Canyon
This page last updated on September 18, 2016.
Copper Era, 1914 to 1936
(Utah Copper, Bingham & Garfield, and Kennecott Copper only)
March 31, 1914
Underground work on Utah Copper's former Boston mine was stopped because enough capping had been removed to allow both mills to be furnished solely from the open cut methods. (Rickard, page 48)
Bingham & Garfield was shut down, until April 27, 1915, for lack of traffic. Copper was selling at 18.5 cents per pound, the highest price since 1907. (Eastern Utah Advocate, April 30, 1915) (Was Utah Copper shut down also?)
Utah Copper took 98 percent of its ore from the open cut operations. Bingham & Garfield moved 4,829,877 tons of ore, 2 percent (100,466 tons) of which was ore from other companies. (Engineering & Mining Journal, May 8, 1915, page 824)
Utah Copper's annual report for the year ending December 31, 1913 shows the following:
During the year 1914, two six-wheel switching locomotives and one No. 8 eight-wheel combination revolving locomotive crane and steam shovel were purchased. At the end of the year, the railway and steam shovel equipment consisted of 20 standard gauge steam shovels ; 39 standard gauge switching locomotives; 1 standard gauge Shay locomotive; 11 narrow gauge locomotives; 100 standard gauge 12-yard all-steel dump cars; 117 standard gauge 6-yard wooden dump cars; 144 narrow gauge 4-yard wooden dump cars; 4 flat cars of 100,000 pounds capacity each; 1 engine tender, used for hauling water; and 1 combination locomotive crane and steam shovel.
Transportation of copper ore for Utah Copper was by way of the Denver & Rio Grande and by its own Bingham & Garfield. Other companies were using Utah Consolidated's cable tramway to the International smelter, and the underground Bingham Central Railway, by way of the three-mile Mascotte Tunnel to Lark. (Wegg, page 68)
Utah Copper ordered six "6-wheel locomotives" from the Baldwin Locomotive Works. (Delivered in October 1915; numbered as Utah Copper 71-76)
November 17, 1915
Guggenheim Exploration Company sold its interest and holdings in Utah Copper to the Kennecott Corporation. (Salt Lake Mining Review, November 30, 1915)
Kennecott Takes Utah Stock -- New York, Nov. 17 -- The Guggenheim Exploration Company, which is a holding company for some of the more important interests represented by the Guggenheims in their various mining operations, is to dissolve, according to announcement made today. The Kennecott corporation, in which the Guggenheims and J. P. Morgan & Co. are said to have large holdings, will take over the holdings of the Guggenheim Exploration Company in Utah Copper, giving its on stock in exchange. Guggenheim Exploration will distribute to its shareholders their pro rata share of holdings of Ray Consolidated, Chino, American Smelting & Refining common and Yukon Gold stocks. In addition, each shareholder of Guggenheim Exploration will receive the option of accepting $37 cash for each share of the new Kennecott stock. The Guggenheim Exploration Company is a New Jersey corporation and was organized as a holding company, with stock interests in various mines and mining properties in Alaska, Canada and the United States, including Utah Copper, Chino Copper, Ray Consolidated Copper, Yukon Gold and American Smelting & Refining Company. The capitalization of the Guggenheim Exploration Company is $22,000,000 and the par value of the stock is $25. Guggenheim Exploration sold at the high record price of 79 3-8 on the stock exchange yesterday and, with other issues of the same group, has been a market leader. This afternoon, on announcement of the proposed dissolution of the company, that stock, as well as most other copper issues, declined moderately.
Utah Copper's annual report for the year ending December 31, 1915 shows the following (selected excerpts):
During 1915, ten 12-yard, all steel, dump cars were purchased, and fifty standard-gauge, 30-yard, all steel, air-dump cars were ordered and will be delivered about April 30, 1916. Some small improvements and extensions were made in connection with the system of water supply for locomotive and steam shovel boilers. A steel frame, corrugated iron, compressor building was erected, and five 6-room brick cottages for heads of departments were built.
The total amount of capping removed during the year was 5,961,367 cubic yards, being an average of 1,490,342 cubic yards per quarter, and an average of 496,780 cubic yards per month, as compared with an average of 1,427,209 cubic yards and 475,736 cubic yards, respectively, for the previous year. The total amount of capping removed prior to January 1, 1916, was 33,795,410 cubic yards, of which quantity 21,194,751 cubic yards were from the Utah Group and 12,600,659 cubic yards from the Boston Group. At the close of the year, the total area upon which stripping operations had been conducted was 203.24 acres, and the actual area completely stripped was estimated at 96.80 acres.
With the exception of a comparatively small amount of development work in the Boston Mine, no underground mining operations were conducted during the year 1915 and, therefore, practically all of the ore produced was mined by steam shovels. The average cost of mining was 24.41 cents per ton, of which 7.50 cents represent charges for stripping and 0.30 cent charges for development, leaving an actual working cost, including the proper proportioning of all fixed and general charges, of 16.61 cents per ton as compared with 22.62 cents per ton for the year 1914. This very notable reduction was due partly to increased output, partly to an improvement in the working conditions on the various steam shovel levels, and partly to increased efficiency in all departments.
During the year, there were milled at the Magna Plant 5,233,300 tons of ore, an increase of 771,839 tons over the previous year; while at the Arthur Plant, which was not operated until January 25th, 3,261,000 tons were milled, an increase of 1,252,295 tons as compared with 1914. The total ore treated at both plants was 8,494,300 tons, as compared with 6,470,166 tons for the previous year. The Magna Plant treated an average of 14,338 tons daily during the year, and the Arthur Plant an average of 9,563 tons daily during the time it was actually operated.
The average grade of ore milled at both plants was slightly under 1.434% copper, as compared with about 1.425% copper for 1914. The average recovery at both plants was 64.13%, corresponding to 18.39 pounds of copper per ton, as compared to 66.04%, or 18.82 pounds of copper per ton, for the previous year. For the last six months of the year, the average daily tonnage milled was 26,537, or about 33% above normal capacity.
The cost of milling at Magna was 30.91 cents per ton, and at Arthur 39.02 cents, as compared with 34.35 cents and 37.55 cents, respectively, for the year 1914. The average cost of milling at both plants was 34.02 cents per ton, as compared with 35.36 cents for the previous year. The average cost for the first quarter was 41.98 cents ; for the second quarter, 30.98 cents ; for the third quarter, 31.66 cents ; and for the fourth quarter, 34.66 cents. The higher costs for the first and fourth quarters were due to winter weather conditions and the consequent decrease in tonnage treated.
About two-thirds of the capping on the westerly side of Bingham Canyon has been removed. On the lower steam shovel levels, stripping has progressed to such an extent that the quantity of capping to be removed from these during 1916 will be only about one-half that moved during 1915. On the levels near the top of the mountain, where the capping was very thick, there is still a large quantity remaining, and it is on this account desirable to continue stripping operations for a time at approximately the same rate as for the past year. It is not likely therefore that any material decrease in these operations will occur until after the close of 1916.
The Directors have authorized the construction of a leaching plant to treat the oxidized capping which has been, and is being, removed from the ore bodies. It is the intention to build this plant with an initial capacity of from 2,000 to 3,000 tons per day, the arrangement being such that this capacity can be readily increased, if an increase is warranted by the experience gained in the operation of the first installation. Construction on this plant will be commenced as early in the summer of 1916 as weather conditions and preparation of designs will permit. For the purpose of furnishing acid for this plant and supplying other local and some commercial requirements, the Company has undertaken to participate equally with the Garfield Smelting Company in financing the construction and operation of an acid works near the smelter.
Utah Copper expanded its original tailings pond near Magna from the original 1500 acres to 5000 acres. This forced the Union Pacific (LA&SL) and Western Pacific tracks to be relocated to the north in 1917. The two railroads created a new station named Garfield as a connection to Utah Copper's railroad. This Garfield station remained in place until replaced by a new Garfield created in 1997 when UP moved its mainline again to allow expansion of the Kennecott tailings pond. (Utah History Cyclopedia; Union Pacific condensed track profile)
Utah Copper sent a representative to Montana to study Butte, Anaconda and Pacific, and Milwaukee Road electrification. (Salt Lake Mining Review, April 15, 1916, page 33)
Utah Copper's annual report for the year ending December 31, 1916 shows the following:
The equipment used in connection with the removal of capping was increased by the addition of fifty standard-gauge 30-yard all-steel air-dump cars. A large additional area of surface was purchased adjacent to the Company's property, for use as dumping ground for waste.
It is estimated that approximately three-fourths of the capping has been removed from the ore body as now developed on the westerly side of Bingham Canyon, and that a total of at least 300,000,000 tons of developed ore yet remains in this part of the deposit. On the lower steam shovel levels, the capping to be removed during 1917 will probably not exceed one-half the quantity removed during 1916; but on the intermediate and upper levels, it will be necessary to continue stripping operations during 1917 at about the same rate as for the year 1916. Therefore, it is not likely that there will be any considerable decrease in such operations during the present year.
In order to furnish acid for the leaching plant and mills, as well as to supply some other local and commercial requirements, the Company agreed to participate equally with the Garfield Smelting Company in the construction and operation of an acid plant near the smelter. The construction of this plant was begun on March 8th, 1916, and the work was far enough along by December 22nd, 1916, to permit commencement of acid production. The operations were hampered by the usual difficulties that are to be expected in starting a new plant, as well as by the unusually severe weather that prevailed all winter. The production has now reached a rate of about 75 tons of 50-degree acid per day. This will be increased gradually to the rated capacity of about 150 tons per day, and it is intended that the plant will be enlarged from time to time to meet not only the requirements of the Copper Company and Smelting Company, but to supply such commercial demand as may be found.
Utah Copper purchased the last of the Wall claims, ending a long series of court battles over the rights to the claims that made up the original Utah Copper property in 1903. (Engineering & Mining Journal, April 28, 1917, page 769)
A 2,000-ton leaching plant was completed at Magna to recover copper from very low grade (less than 1 percent) ore. Construction started in August 1916. (Kennecott notes; Engineering & Mining Journal, July 1, 1916, page 71)
New crusher was installed at Arthur. (Kennecott Historical Index)
Bingham & Garfield hauled an average of 32,019 tons of copper ore per day. (Kennecott Historical Index)
A new Wellman-Seaver-Morgan single car dumper was installed at Arthur. The mill had originally been equipped with a 10,000-ton steel ore bin fed by bottom dumping ore cars. (Rickard, page 53) (Kennecott's Historical Index says that the dumper was a "Hullett Single".)
Operations of new Magna leaching plant began. (Kennecott notes)
January 15, 1919
First operation of new car dumper at Arthur. (Kennecott Historical Index)
February 26, 1919
Magna mill was closed because of drop in copper demand after World War One. The mill had been working full time since opening in 1908 and needed maintenance. The shut down lasted over 2-1/2 years, until November 10, 1922. (Arrington: Richest Hole, page 70; Parsons 1933, page 87)
May 28, 1920
An agreement was signed for the operation of Utah Copper ore trains over the Bingham & Garfield, by Bingham & Garfield crews. (Kennecott Historical Index)
September 1, 1920
All Bingham & Garfield locomotives and rolling stock were sold to Utah Copper Company, to remove the B&G from interstate commerce, and limit the railway company's net operating income to 6 per cent, the figure established by the federal Interstate Commerce Commission; any amount exceeding 6 per cent was to deposited into a nationwide revolving fund for the benefit of all of the nation's railroads.
On March 1, 1920, the United States Railway Administration had returned control of the nation's railroads, from government control due to World War I, back to the railroad companies. Included in the enabling Esch-Cummins Act was a provision to allow the ICC to control the railroads profits and rate of return for investments. (Esch-Cummins Act) (USRA)
During 1921, Utah Copper was using 21 steam shovels, and 49 standard gauge steam locomotives and 11 narrow gauge steam locomotives. (Moody's Manual Of Railroads And Corporation Securities, Twenty-Third Annual Number, Industrial Section, Volume II, K to Z, 1922, page 1235)
Magna leaching plant was shut down permanently due to the low price of copper, and the high cost of the leaching operation. The plant was under construction between September 1916 and September 1917, and had been in operation from January 1918 to February 1919 and again in May 1920 through February 1921. (Kennecott notes)
"Utah Copper company which produces most of the copper in Utah, was active in January, February, and March of 1921, and produced nearly 24,000,000 pounds of copper, but the mine was closed in April." "Utah Consolidated Mining company, a producer of both copper and lead closed its mine at Bingham in February." "The United States Mining company has continued to ship lead-zinc ore from Bingham, but the Utah Apex and Utah Consolidated mines, both large producers of lead, were closed." (Ogden Standard Examiner, July 13, 1921, citing a July 13 report by USGS, "Metal Output To Drop Low, Utah's Production This Year To Show Big Dropping Off")
April 2, 1921
Bingham Canyon mine was shut down. (Kennecott Historical Index)
April 4, 1921
Arthur mill was shut down. (Kennecott Historical Index)
First electric shovels were tested at Bingham: two Marion Model 92 shovels with treads and 4-1/2 yard dippers. (USGS Bulletin 398, page 184) Electric shovels had been used in other parts of the world as early as 1914 (an electric Bucyrus Model 100-C having been used in Sweden). (Engineering & Mining Journal, October 31, 1914, page 767)
April 1, 1922
Bingham Canyon mine operations resume. (Kennecott Historical Index)
April 4, 1922
Operations at the Arthur mill resumed. Production at the Bingham mine was to be between 2,000 and 3,000 tons per day for the next several weeks. A total of 550 men were employed by Utah Copper Company: 170 men at the Bingham mine; 80 men on the Bingham & Garfield Railway; and 300 men at the milling plants. Three shovels were at work in the Bingham mine; one making a grade change on the 'F' level, and two loading ore. (Weber River Independent, April 7, 1922, citing a statement from Utah Copper Company, April 4 was a Tuesday)
Modernization of Magna mill began. (Kennecott Historical Index)
Magna mill was reopened. (Kennecott Historical Index)
Utah Copper was reported as shipping 250 cars per day (about 25,000 tons) by way of the Bingham & Garfield Railway. "None of this immense tonnage has been handled by Denver & Rio Grande Western for three years." (Salt Lake Mining Review, November 15, 1922)
A test precipitation plant was built in the bottom of the pit to recover the dissolved copper in drain water which collected at the bottom of the pit. (Arrington: Richest Hole, page 74)
Steam shovels were remodeled by placing them on three caterpillar treads, one on each side at front, and a third in center at rear. (Bureau of Mines IC 6234)
Wellman-Seaver-Morgan Twin car dumper was installed at the Magna mill. Magna had originally been equipped with a 25,000-ton wooden ore bin with three tracks dumping into it. Cars being dumped were either wood or steel and either center-bottom dump or side-bottom dump. Bottom dumping was becoming a problem due to large boulders and wet ore freezing during the winter. The new twin car dumper was capable of dumping 720 cars (48,000 tons) per day. (Kennecott Historical Index)
Two electric shovels and 17 steam shovels were placed on caterpillar treads. Treads had been in use on shovels in other mines in country since 1920. (Kennecott Historical Index)
Utah Construction Company began excavation for the new car dumper at Magna. (Mining and Metallurgy, August 1925, page 447)
First new electric shovel purchased. (Bureau of Mines Bulletin 273, pages 2,3)
November 12, 1923
First new electric shovel (number 22, a Marion Model 92), of eight purchased new, was placed in service at the north end of K-Level. Fifteen steam shovels had been converted to electric at the Bingham shops. (Kennecott Historical Index) (Read more about how Utah Copper numbered the levels of the Bingham mine)
Magna car dumper yard was completed and the new car dumper was placed into service. (Kennecott notes)
A small precipitation plant was built at Copperton to extract copper from waste dump runoff. (Arrington: Richest Hole, page 74)
June 16, 1924
Two 70-ton, 600 volts DC electric locomotives arrive for use at the new Magna and Arthur dumper yards. (Kennecott notes)
The Magna and Arthur dumper yards were electrified, using 600 volts DC, and the two 70-ton locomotives go into service, one at Magna on September 8th and the other at Arthur on September 10th. (source not recorded) (The two locomotives were purchased second-hand from Manufacturer's Railway in St. Louis.)
Six new electric shovels arrive. Three steam shovels converted to electric. The decision was made to electrify all remaining shovels. (Bureau of Mines Bulletin 273, page 3)
On September 21, 1925 Denver & Rio Grande Western sold the Copper Belt Branch, the Yampa Branch, and the upper (in-canyon) portion of the Low Grade Line to the Bingham & Garfield Railway. (D&RGW Agreement 4163 and Deed U-3267) The location of the three lines were interfering with the expansion of Utah Copper's open pit mine. The copper company wanted the freedom to move the trackage around to suit the operations of the mine. The Rio Grande retained its yard and depot at Bingham and 3.3 miles of the Low Grade Line outside of the canyon, which they renamed the Bingham Branch Extension. That portion of the line was being used to serve the loading bins of the Congor and Midas mines and was later abandoned in 1931. By the time of the 1925 sale the Copper Belt Branch was thoroughly intermixed with the trackage of the copper company. The Yampa Branch had not been operated since 1913 and had seen very little traffic since the Yampa Smelter was destroyed by fire in 1909. Most of the other mines were owned by the larger companies but were being worked by leasers. Their ore bins would be served by the Bingham & Garfield, as a common carrier.
The five Shay locomotives purchased by the Denver & Rio Grande as part of its purchase of the Copper Belt Railroad had been kept working on the branches in the canyon, above Loline Junction. With the sale of the three branches with steep grades and sharp curves in 1925, Denver & Rio Grande would likely have moved the Shays from their former Copper Belt location at Bingham down to the roundhouse and facilities at Welby. Three of the Shays, road numbers 1, 2, and 4, were sold for scrap within a year and a half. The two others, numbers 3 and 5, were kept in service for another eight and ten years respectively, when they too were sold and cut up for scrap.
By 1926 Utah Copper was shipping 50,000 tons per day over the Bingham & Garfield Railway, compared to the 35,000 tons that the Copper Belt had shipped during the entire month of October 1904.
Capacity of Magna and Arthur mills were raised to 50,000 tons per day. (Kennecott Historical Index)
Construction of "model" townsite of Copperton was begun. (Kennecott Historical Index)
late April 1926
Utah Copper ordered two locomotives for motive power tests in the Bingham Canyon mine, to be delivered within 90 days; one was to be a 60-ton oil-electric at a cost of $65,000 (road number 600) and the other was to be a 75-ton combination trolley electric/battery electric at a cost of $50,000 (road number 700). Both locomotives to be used on 'J' and 'K' stripping levels. No mention of tests involving steam motive power. (Salt Lake Mining Review, April 30, 1926)
"Large shovels at Bingham are already electrified." (Salt Lake Mining Review, April 30, 1926)
An ALCo-General Electric-Ingersoll Rand 60-ton oil-electric locomotive number 600 was received. (construction serial number 10028/16680) (builder's data)
August 24, 1926
Date of photo showing the new 'D' bridge being built across Carr Fork.
May 16, 1927
First electric locomotive, number 700 (GE construction serial number 10258), was put into service on the K-Level dump line and comparative tests between diesel and electric were begun. Electric power to the locomotive was 750 volts DC and came from portable towers of the same design as those being used for the 550 volts DC for the electric shovels. (Kennecott Historical Index)
The first electric locomotive at the Bingham mine was put into service in 1927 on "G" level dump. (Kennescope, no date)
The conversion of the 90-ton shovels from the steam railroad type with 3-1/2 cubic yard buckets to electric with caterpillar treads and 4-1/2 cubic yard buckets had allowed a 68 percent increase in productivity, from 2,350 tons to 3,966 tons per shovel per day. Twenty three all-electric shovels were in service, eight using AC controllers and fifteen others using DC controllers. (Kennecott Historical Index)
March 27, 1928
D&RGW converted a retired engine tender for use as a water car for added capacity of its 3400-series 2-8-8-2 (Class L-95) locomotives assigned to the Bingham Branch. (D&RGW AFE 3711, courtesy of Jerry Day)
The New York Times reported on May 2, 1928, that Kennecott Copper Corporation owned 97-1/2 percent of Utah Copper Company, which in turn owned 43 percent of Nevada Consolidated Copper Company. (New York Times, May 2, 1928)
Utah Copper announced that they would replace their steam railroad locomotives with combination electric trolley and battery locomotives, some of which would be built with an additional cable reel for "extension cord" operation. (Kennecott Historical Index)
The first of the new electric locomotives arrived. The first to arrive was number 702. Apparently number 701 was wrecked en route and Utah Copper never replaced it. (GE builder data)
Precipitation plant at Copperton was replaced by a more modern one of greater capacity. (Arrington: Richest Hole, page 74)
September 23, 1929
Electric locomotives placed in service in Bingham & Garfield Bingham yard as switchers. (Kennecott Historical Index)
Last (number 741) of the initial 40 (road numbers 701-741) electric locomotives was received. (Kennecott Historical Index)
December 19, 1929
Centralized Traffic Control (CTC) was placed in service at the pit. Forty-one (41) 85-ton electric locomotives are in service. (Kennecott Historical Index)
Sixty miles of track were in service in the pit with an average daily production of 40,000 tons of ore and 30,000 cubic yards of waste removed. (Kennecott Historical Index)
January 25, 1930
Arthur mill was shut down for rehabilitation. All ore was then treated at Magna. The Arthur remained closed until September 1936. (Kennecott Historical Index)
Grading work was begun at Arthur to raise the dumper yard to the level of the car dumper. The project was completed in May. Up to this time the dumper was about ten feet above the tracks of the dumper yard and an electric pusher "mule" was used to push the ore cars up to the dumper. The "electric mule" cable car pusher had become troublesome in the winter and could not handle the desired increased dumping rate. The cost of the project was $100,000 and it allowed for increased daily capacity of 500 cars, or 40,000 tons. (source not recorded)
May 3, 1932
Kennecott Copper Corporation, which owned 98 percent of Utah Copper Company, offered to acquire Nevada Consolidated Copper Company, at the rate of one share of Kennecott for two shares of Nevada Consolidated. At the time, Kennecott, through its Utah Copper subsidiary, owned 45 percent of Nevada Consolidated. (New York Times, May 4, 1932, "yesterday")
June 11, 1932
Kennecott's offer to exchange its stock for Nevada Consolidated stock was set to expire on June 15, 1932. To allow for stockholders who were abroad, Kennecott's offer to exchange its stock for that of Nevada Consolidated was extended through July 15, 1932. By June 11, 1932, Kennecott, through its Utah Copper subsidiary, owned 75 to 80 percent of Nevada Consolidated. On July 15, the offer was extended to September 15. (New York Times, June 11, 1932; July 17, 1932)
February 3, 1933
Kennecott Copper Corporation owned 98-1/2 percent of Utah Copper Company. After the distribution of Nevada Consolidated Copper to Utah Copper stockholders (in other words, Kennecott) on or before February 14, 1933, Kennecott would own and control 87 percent of Nevada Consolidated Copper Company. One year before, at the end of 1931, Utah Copper held 31 percent of Nevada Consolidated. (New York Times, February 5, 1933)
A ten-feet wide, electrified railroad tunnel under all of the mines in Bingham Canyon was proposed in a request for a $2.5 million government loan from the Reconstruction Finance Corporation. The tunnel was to be 30,000 feet in length and would connect the bottom workings of a "dozen" mines, allowing them to haul their ores down to the new tunnel, rather than hoisting their ore up several hundred feet at great expense. (New York Times, November 19, 1932, "Mine Tunnel Loan Sought")
Bingham Canyon mine and Magna mill operations were at one-fifth of capacity, with staggered shifts to retain as many workers as possible. (Arrington: Richest Hole, page 71)
May 16, 1934
D&RGW retired its 60-foot turntable at Bingham. (D&RGW AFE 5227, courtesy of Jerry Day)
April 1, 1935
Utah Copper's operation of the Bingham & Garfield, known as the Ore Delivery Department,was placed under the administration of the Department of Mills. (Kennecott Historical Index)
September 1, 1936
Arthur mill reopened, after being shut down for nearly six years. The Arthur foundry reopened in October 1932, after closing in January 1932. (Kennecott Historical Index)
November 10, 1936
Utah Copper Company was sold to Kennecott Copper Corporation. Kennecott had organized a new Utah Copper Company in Delaware, as a subsidiary, on November 6, 1936 for the purpose. The original Utah Copper Company had been organized in New Jersey in 1904. On April 29, 1915, Kennecott Copper Corporation had been organized in New York to acquire the worldwide Guggenheim copper interests, including all of the interests of Kennecott Mines Company in Alaska (including its Copper River & Northwestern Railroad) and 25 percent interest in Utah Copper Company in Utah, along with 96 percent interest in Braden Copper Company in Chile. In 1923 Kennecott Copper Corporation acquired 77 percent control of Utah Copper Company and by 1925 Kennecott had acquired 95 percent interest in Utah Copper. (Arrington: Richest Hole, page 68; Kennecott Historical Index)
(The story continues after 1936)
(see also Kennecott parent companies)