A History of Gold Dredging in Idaho

Clark C. Spence

• Publisher: University Press of Colorado
• Year: 2016
• Print ISBN: 9781607326212, 9781607324744
• eBook ISBN: 9781607324751
• Topic: History
• Subtopic: North American History
• Index: History

A History of Gold Dredging in Idaho tells the story of a revolution in placer mining—and its subsequent impact on the state of Idaho—from its inception in the early 1880s until its demise in the early 1960s. Idaho was the nation's fourth-leading producer of dredged gold after 1910 and therefore provides an excellent lens through which to observe the practice and history of gold dredging.

Author Clark Spence focuses on the two most important types of dredges in the state—the bucket-line dredge and the dragline dredge—and describes their financing, operation, problems, and effect on the state and environment. These dredges made it possible to work ground previously deemed untouchable because bedrock where gold collected could now be reached. But they were also highly destructive to the environment. As these huge machines floated along, they dumped debris that harmed the streams and destroyed wildlife habitat, eventually prompting state regulations and federal restoration of some of the state's crippled waterways.

Providing a record of Idaho's dredging history for the first time, this book is a significant contribution to the knowledge and understanding of Western mining, its technology, and its overall development as a major industry of the twentieth century.

1
Early Snake River Boom

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From its origins on the Continental Divide in the Teton Range in western Wyoming, the Snake River flows southward in a large arc across southern Idaho, then forms that state’s western border as far north as Lewiston before it meanders westward to its eventual confluence with the Columbia in southern Washington. Since as early as the 1850s, when soldiers at the old Fort Boise made limited discoveries, gold has been found along most of the 800-mile course through the Gem State. Optimistic bands of prospectors moved south to expand operations in the 1960s, without much success, but in the 1970s many of them located workable placer ground in scattered sites, among them the Shoshone Falls region, the area near J. Matt Taylor’s bridge (which became Idaho Falls), the Hagerman Valley, below the Raft River, and west of American Falls. But these were scattered small-scale, labor-intensive operations that spawned no serious influx of capital or miners as long as a major obstacle existed. It was the nature of Snake River gold itself that provided the real challenge to profitable mining.¹

By 1880 Snake River gold had been recognized as constituting extremely fine particles—some so small that it took 1,000 to make up the value of a penny. Others were even more minute, and the 3,000 or 4,000 particles required to make up a penny’s worth of gold could not be recognized at all: invisible gold was the miners’ description and micron gold was a more modern term.² Early scientists believed the fine gold came from the waters of a Miocene lake, but modern geologists have determined that it came from Rocky Mountain deposits and that it originated as minute particles.³ Scattered the length of the stream, this “flour” or “float” gold appeared in river bar deposits, as well as in “skim bars” and “bench gravels” on the bank. A skim bar was an ancient river bar, in which the gold was found near its top, while bench gravels were higher up and gold was found in streaks anywhere between bedrock and the surface.⁴

To many observers, the Snake River placers seemed a promising field for the gold dredge, a relatively new technology that had proved successful in New Zealand and which, after years of experimentation, was beginning to catch on in California, Montana, and other western states. The stream’s current ran at a moderate rate of three miles an hour, severe flooding was rare, and the climate permitted operation for nine or ten months of the year. Best of all, according to optimistic reports, there were “oceans of gravel,” which showed values of from thirty cents up to five dollars with a pan or a rocker. The belief that there was a wealth of gold in and along a great portion of the river’s length was common, although few of the numerous miners since the 1860s were taking out more than day wages.⁵ In 1899 Don Maguire, a self-taught Utah mining man, estimated that the gravels contained at least $2 billion in gold.⁶ A popular Oregon writer noted a year later that “men, to-day, dredging the sandy bed and banks of the river Snake say there is fine gold enough in the drifts and bars alone to pay the national debt over and over again”—words Boise businessmen echoed enthusiastically.⁷ Since paydirt was usually on or close to the top of the bars, deep dredging seemed unnecessary. At least that was what mining analysts of the late nineteenth and early twentieth centuries believed, thus setting the stage for a brief era of gold-dredging activity along the Snake. No wonder there were so many repeated efforts to apply a more advanced technology. Unfortunately, on the Snake it was a high-interest, low-success industry.

The period prior to about 1910 was largely a time of trial-and-error experimentation, often by self-styled experts testing their own inventive machines and processes. Some mining men welcomed attempts to apply modern technology; others dragged their feet, holding fast to the old ways of doing things. The new dredging ideas on the Snake extended from around Huntington in Oregon to east of Idaho Falls and were especially prominent in the region from Weiser to perhaps Caldwell, with lesser applications in the stretch from Grand View, Bruneau, and Glenns Ferry. Momentum on the river picked up again from Minidoka through American Falls, Blackfoot, and Idaho Falls. Only a single company organized for dredging on the Snake in the Jackson Hole region of Wyoming has been noted.⁸

One of the first efforts to utilize yet unproven dredge equipment on the river was first announced to the public at the end of 1881, with the arrival in Boise of four Detroit businessmen en route to Starrh’s Ferry on the Snake. This quartet—George C. Fletcher, T. H. Champion, E. M. Hough, and John Shiri—had obtained ground near the mouth of Goose Creek and intended to apply the new technology there.⁹ According to the Salt Lake Tribune that December, John F. Sanders of Ogden had investigated the Snake River placers beginning in 1870 and experimented with saving the fine gold and processing the black sands previously cast aside. He was convinced that machinery could be applied, and subsequently he patented the Sanders Ore Concentrator and the Sanders Patent Vacuum Dredge.¹⁰ In addition, he held Letters of Patent on “Composition for Dissolving the Coating of Gold Ore,” in essence a simple chemical formula for breaking down the black sands. The secret was sixteen parts of potassium cyanide to one part of glacial phosphoric acid, with the solution mixed in an iron barrel (or one made of some “other proper material”) with enough water to form a pulp with the sand and gravel, then agitated in the container for fifteen minutes to an hour. The result would be gold pure enough to amalgamate with mercury.¹¹ (Was this a forerunner of the cyanide process?) Four companies were formed to operate between American Falls and Salmon Falls: one by investors from Detroit, another by Boston capitalists, a third with money from Detroit and Buffalo combined, and a fourth by men from Salt Lake City. It was contemplated that all machinery would be afloat and that some rigs would handle 100 tons of gravel in a ten-hour workday and others would handle twice that amount.¹²

Finally, in the spring of 1882, according to a correspondent for the Chicago Mining Review, two dredges built under Sanders’s patents conducted initial trials near the Goose Creek ferry—a mile west of the modern town of Burley. They were owned by two Detroit companies, the presidents of...

Table of contents

• Cover
• Title Page
• Contents
• Acknowledgments
• Introduction
• 1 Early Snake River Boom
• 2 The Black Sands Craze
• 3 The Burroughs Brothers
• 4 Pierce
• 5 Florence
• 6 Elk City and Newsome
• 7 Stanley Basin and Yankee Fork
• 8 Salmon City and Leesburg
• 9 South and Middle Forks of the Boise River
• 10 The Yukon Dredge
• 11 Warren
• 12 Boise Basin
• 13 Dredging Rare Metals
• 14 Other Dredge Grounds and Snake-Salmon Rivers
• 15 The Struggle for Dredge Control
• 16 Aftermath: The Cleanup
• 17 Overview
• Epilogue
• Brief Bibliographic Essay
• Index