Teller County stood first in gold production in Colorado.
There was a revival of mining in Georgia.

The Ramshorn and Bayhorse, Custer County, Idaho, were the deepest and best developed copper-silver mines in the state.

The Tonopah district, Nevada, was discovered by James Butler. Electrical power was introduced into the Tonopah district, and the development of the Tonopah Lake district was stimulated by a system of small leases.

There was great activity in the construction of cyanide mills in South Dakota, although the mining of gold was confined largely to the Black Hills.

Gold was discovered in Box Elder County, Park Valley, Utah, during 1900-01.

1901.

The smelting interests of the Guggenheim's Sons were absorbed by the American Smelting and Refining Company, the former becoming, however, the dominating factor in the amalgamated company. The American S. & R. Company assumed control of the lead market, fixing the price both for the producer and consumer, and regulating the output by agreement with the large producers, and by adjustment of its smelting charges in connection with small producers.

There were eleven cyanide plants operating in South Dakota.

The mining interests of Tombstone, Arizona, were consolidated, following which the district again became an important mining center. Gold was found on Thunder Mountain, Idaho.

The Oregon King mine, Oregon, was opened.

1902.

There was considerable activity in mill construction in Nevada, especially at the De La Mar mine.

The Sierra de Mogollon properties, in New Mexico, were developed.

Dredging was successfully carried on in the Moreno Placers, Colfax County; also at Grant, Sierra, Santa Fé, Taos, Lincoln and Socorro, New Mexico.

Practically all of the Republic mines, Washington, were operating. There was considerable excitement in the Wichita Mountains, Oklahoma, during 1902–03.

Gold was found in glacial drift at St. Croix Falls, Wisconsin.

The output of the Coeur d'Alêne district was limited by arrangement between the leading producers and the Am. S. & R. Company. Further steps were taken by the smelting combine to centralize the smelting operations, the Philadelphia plant, at Pueblo, Colorado, being closed, and the famous smelter and refinery at Argentine, Kansas, was abandoned and dismantled.

A cyanide plant was installed at the Smuggler-Union mine. Colorado produced more than one-third of the gold and onefourth of the silver product of the United States. Alaska followed with one-ninth of the total gold output, while she contributed more than one-half the placer gold of the United States. Montana held second place as a producer of silver, having produced nearly onefourth of the silver in the states. Utah stood third in rank as a silver producer.

Australia held first place in the gold production of the world; the United States came second, Russia fourth, and Canada fifth.

Mexico led in the production of silver, the United States being a close second.

There was a serious depression in the mining industry of Colorado, owing to the decline in silver and exhaustion of a number of large gold mines.

The Parks and Columbia mines of Georgia were the largest producers.

J. T. Lovewell reported finding from $2 to $10 in gold and silver per ton in the ores of Western Kansas; officials of the United States Geological Survey examined the district, but found only traces of gold and very small amounts of silver.

The gold deposits of Columbia Mountain, Tonopah, Nevada, were discovered.

1903.

The Federal Mining and Smelting Company effected a consolidation of many of the large mines of the Coeur d'Alêne district.

The Western Mining Company was organized as a subsidiary company of the Guggenheim Exploration Company, and acquired several of the large lead-producing mines at Leadville, Colorado.

In July there was a strike of the smelter-men at the Grant works of the American Smelting and Refining Company, and as a result the plant was closed and abandoned.

The first shipment of gold was made from the Combination mine, Nevada, which was discovered the same year.

There was considerable active development in the Bradshaw Mountain district, Arizona.

The passage of the eight-hour law was an important event in mining circles, Arizona.

The Cripple Creek drainage adit was started and completed, connection being made with the El Paso mine on September 6.

The Old Gold mine on Beacon Hill, Colorado, was discovered.

The extension of the Montana railroad from Harlowton to Lewistown was completed and stimulated the gold mining industry of Fergus County, Montana.

There was a falling off in the gold production of the Mercur camp, Utah.

1904.

Probably the first successful application of the cyanide process to low-grade Southern gold ores was made at the Colossus Gold Mining and Milling Company's plant.

Australia still led in the production of gold; South Africa came second and the United States third.

Owing to the lowering of the water-level in the Cripple Creek mines, Colorado, new discoveries were made.

The Harlson County placers of Georgia were worked.

Silver was still the most important product in Idaho.

Telluride ores were discovered at the Iron Spring mine on Rapid River, Idaho.

The Whitlace mine, Montana, was reopened after lying idle for 27 years.

Interest centered chiefly in the Cornucopia camp, sixty miles south of Baker City, Oregon.

There was a marked increase in the gold and silver production chiefly from the Bingham district, Utah. Increased railroad facilities stimulated the districts in the southern part of the state. Connection was made with the Pacific coast.

Both the gold and silver product of Washington had increased; the Sherman district began to attract attention.

1905.

Most of the gold produced in Utah came from the smelting of copper ores.

The Huntington-Heberlein process was adopted by the Am. S. & R. Co.

Many old mining camps, including Cerro Gordo, California, and Eureka, Nevada, began to attract attention again. The Eureka and Richmond companies were consolidated.

The Selby works at San Francisco was purchased by the Am. S. & Securities Company, a subsidiary company of the Am. S. & R. Co. The United States Smelting and Refining Company was organized which took over several independent works, with plans to enter into competition with the Am. S. & R. Co.

During this year nine states and territories produced 99.5 per cent of the gold ouput of the United States, the more important being: Colorado, California, Alaska, South Dakota. Montana led in silver production, being followed closely by Colorado and Utah. Idaho was beginning to be an important factor in the production of silver which came chiefly from silver-lead ores.

The United States led in the production of silver, Mexico being second.

The principal source of gold in Arizona was from the copper ores. There was a pronounced increase in the gold output of California. The gold production of Idaho decreased somewhat.

Four-fifths of the silver came from the Butte copper mines, Montana. Fergus County led as a gold producer, Kendall being the chief center.

The only placers worked in Montana were those on Grasshopper and Rattlesnake creeks.

The Tonopah district was the most important in southern Nevada, the Tonopah mine being first and the Montana second in import

ance.

Gold dredging had become a fixed and profitable industry in California.

1906.

An electrolytic lead refining plant was erected by the U. S. S. & R. Co., near Chicago, which was the first work of this kind in the United States. The Guggenheims had practically secured control of the National Lead Company, thus bringing the larger part of the leadconsuming industry of the United States into direct affiliation with the Am. S. & R. Co.

Steam shovels were employed in the Boston Consolidated Mining Company's mines, at Bingham, Utah.

The Idaho mine, Clay County, Alabama, was opened, and dredging was done on the Chestatee River.

CHAPTER III.

OCCURRENCE AND ASSOCIATION OF GOLD AND SILVER.

No attempt at an exhaustive discussion of the theory of oredeposits is undertaken in this connection; however, it would seem to be both necessary and desirable that so much of the generally accepted theories should be given as to render the following information more intelligible to the reader. Extracts from various papers on the theory of vein structure and deposition of minerals are quoted freely, references being given in order that the reader may be able to refer to the full text should he so desire.

1

Theory of Ore Formation and Occurrence of Gold in Gravel. - In J. F. Kemp's paper on the Formation of Veins is an excellent discussion and summary of the principles involved, from which the following extracts are taken.

"All problems of ore deposition resolve themselves into three main parts. The first is the geological structure of the immediate country. The second includes the solvent or introductory medium and its prime mover. The third relates to the chemical reactions

involved.

"Under the first we raise the question, Why has the particular spot been selected by the depositing agents? Granted, as is usually the case, that some fluid has been the vehicle of introduction, this phase of the problem becomes one of explaining cavities and waterways." The usual receptacles for mineralized solutions and the minerals subsequently deposited from them are porous rock and openings produced in rock masses by folding and faulting and often by the natural process of cooling of molten or heated bodies of mineral matter.

"Inasmuch as the greater number of ore bodies have been obviously precipitated in cavities and by the medium of some solvent, all careful observers have at once pitched upon water as the necessary vehicle. However widely one writer may differ from another in the emphasis laid on the condition of the water, whether hot or cold, whether derived from the vapors held by the igneous and molten The Formation of Veins, J. F. Kemp, Mining Magazine, Vol. 10, p. 89.