In 1919-1920 the Mining Department was organized into four main geographical divisions, with the field work delegated to a mining engineer in each district working out from field offices that were established in Redding, Auburn, San Francisco and Los Angeles, respectively.

This move brought the Bureau into closer personal contact with operators, and it has many advantages over former methods of conducting field work.

To continue this system most effectively with the limited funds available for the present biennium, the Redding and Auburn field offices were consolidated and moved to Sacramento on June 1, 1923.

The boundaries of each district were adjusted and the counties now included in each of the three divisions, and the locations of the branch offices, are shown on the accompanying outline map of the state. (Frontispiece.)

Reports of mining activities and development in each division, prepared by the district engineer, will continue to appear under the proper field division heading.

Although the petroleum industry is but little affiliated with other branches of mining, oil and gas are among the most valuable mineral products of California, and a report by the State Oil and Gas Supervisor on the current development and general conditions in the state's oil fields is included under this heading.

SACRAMENTO FIELD DIVISION.

C. A. LOGAN, Mining Engineer.

NOTES ON MINING DURING THE YEAR 1923.

Although mint and smelter returns in 1923 show a falling off in actual production of gold in California from the 1922 figures, the past year has been a fairly good one for the gold mines. Production costs have remained high and the industry has suffered from a heavy labor turnover, but, in spite of these handicaps, development work has continued, new activities have been initiated and in the leading mining counties of the State and along the Mother Lode the outlook for increased activity and output in 1924 is most encouraging. The estimated production for 1923 is $13,250,000. Among the principal producers are the dredges of Yuba Consolidated Goldfields and Natomas Company of California; Empire Mine at Grass Valley; Carson Hill Gold Mines, Inc., at Melones; Sixteen to One Mine, at Alleghany; Plymouth Consolidated Mine, at Plymouth; North Star Mines, at Grass Valley, and Kennedy Mine and Central Eureka, in Amador County.

Amador County.

Recent developments in the deep mines in this county as well as at Carson Hill in Calaveras County and at Grass Valley, make it appear that those geologists who have maintained that gold quartz mines invariably become leaner as the depth of working increases, will have to qualify their statement by citing an ever increasing number of California mines that are exceptions to their rule. The limit of some of

these deep mines may be determined by the costs of operation, and not by a diminution in the grade of ore. The bottom levels of such mines as the Argonaut and Kennedy are showing strong fissures and very flattering prospects and it has recently been said that these deep Mother Lode mines are apt to be as rich at the great depths attained as they ever were. Of course it does not follow that all the mines along this 'Lode' will be as rich, at great depth, as there are special geological conditions encountered in every property.

Argonaut Mine. During the first four months of the year the shaft and adjacent workings were repaired, after which repairs and replacements were made on the hoist and the shaft was concreted to a depth of 40 feet. The lower levels were unwatered and milling was resumed about the middle of the year, first with 20 stamps and about the middle of July with 40.

The mine is opened to an inclined depth of 4800 feet. Just previous to the last fire the south drift on this level was showing a width of 20 feet of quartz, and ore was being developed along the vein in new territory south of the region that had marked the limit of good ore in the levels above. Current reports are that this region is giving satisfactory results.

Bunker Hill Mine came under the control of the owners of the adjacent Original Amador Mine this year and it was hoped that the two mines would be worked as a unit, using the Bunker Hill shaft to explore the lower part of the Original Amador, but nothing came of it.

Central Eureka Mine continued mining and milling throughout the year, but not on as high a grade of ore as the previous year. The workings reached an inclined depth of 4100 feet early in the year. Many improvements such as a new headframe, new rails in the shaft and shaft repairs have been made.

Fremont Mine. The mill at the Fremont Mine was put in operation. the middle of March after Metals Exploration Co. had spent a long time in repair work and prospecting. The mine and mill have since been in steady operation. About the middle of August, Metals Exploration Co. gave up the property and a new company, known as FremontGover Mines Company, was organized. The directors of the new concern are Edwin Higgins, Roy Elliott, William Colby, S. A. Holman, and E. E. Check.

Due to the fact that considerable ore had been previously developed in the mine, the recent operations have shown a low cost. The mill was handling about six tons per stamp per day in August with 35 stamps in operation on ore of ordinary Mother Lode grade. The company is at present selling stock and the mill is operating.

Kennedy Mining and Milling Company has sunk its shaft from the 4050 to 4200 ft. level (vertical) and has crosscut on the 4200 level recently, with the work still going on as this is written. A width of 20 feet where the crosscut went through the footwall vein has been reported to assay so well that the owners are greatly elated, more particularly since this came close on the heels of the last stock assessment. After passing through the footwall vein the crosscut was being continued through the horse toward the East Vein and had reached a

length of 70 feet when this was written. It was said this entire distance assayed well, but this has not been substantiated.

The Kennedy has suffered a number of interruptions to operation during the past year, and production has been much below normal.

Marklee Mining Company. Jos. L. Del Monte, president, Federal Bldg., Oakland, Cal. Organized to work the Marklee and Alturas Mines, five miles north of Volcano. According to early U. S. government reports the Marklee Mine began production in 1869 and for several years yielded good ore. A boiler, hoist and new headframe have been installed and the old shaft had been partly cleaned out and retimbered late in the fall, with work continuing.

Moore Mining Company has sunk the shaft at the Moore Mine 100 feet and has opened a new level at 640 feet, where the ore body was encountered on the south after about 70 feet of drifting. The difficulty of sinking and keeping the mill running with a single drum hoist was to be overcome by conversion to a double drum hoist, according to plans announced. Milling with 20 stamps was resumed the middle of July. The first clean-up thereafter showed an average yield of $6.82 per ton.

Old Eureka Mine was sold under foreclosure in July to Walter Harper of New York. This sale is the aftermath of the recent extensive operations about 1920, and the hope has been expressed that with the clearing up of the ownership there might be some action toward reopening.

Oleta Gold Mining and Milling Company has been doing some development work on the L. Smith property near Oleta and has lately been sinking a shaft.

Original Amador Mine was held in readiness for operation until late in the summer, when it was said plans for work had been given up.

Plymouth Consolidated Gold Mines have remained in steady operation during the year and have been one of the principal producers of the county. The operations reached a depth of about 4000 feet and a level was opened at 3850 feet early in the year. The deeper operations have been through a winze, but it has been planned to deepen the shaft if the prospects justify. William J. Loring, general manager. Stanley Arnot, superintendent.

PLACER MINES.

American Flats Gold Mining Company announced they would begin operation at Oleta in July.

Elephant Deep Hydraulic Mine was in operation as long as water lasted the past spring and it was stated that the cleanup amounted to $15,000. Preparations were under way in the fall for a resumption of work. The mine is in the Volcano district and has been worked under lease by Barone Bros. of that place.

Ludekins Hydraulic Mine in the Volcano district was also operated. the past season.

Calaveras County.

COBALT.

During the past two years several samples of cobalt diarsenide (smaltite) with erythrite, have been brought to the attention of the Bureau. These apparently came from a single small prospect, which was visited in November, 1923. It is in the northwest quarter of Sec. 21, T. 4 N.; R. 14 E.; about a mile by trail from the Murphy-Sheep Ranch road and on top of a ridge at an elevation of over 3000 feet. A surface cut 15 feet long and 3 feet deep had been made on a stringer of the ore. This had been only a few inches wide between a mica schist footwall and quartzite hanging wall, and had pinched out, so far as could be seen, both on the dip and strike. Only a few hundred pounds of ore had been found, but samples indicated it was of good grade. The claim was idle and the ownership uncertain. It was stated that some work was planned by R. C. Johnson.

COPPER.

Extensive improvements and additions, including enlarged power supply, have been under way at the properties of the Calaveras Copper Company at Copperopolis during the summer and fall. Actual production was started late in December.

GOLD QUARTZ MINES.

Apex Mining Company, 78 Bacon Building, San Francisco, Henry Hyde, president. This is a new stock company based upon the Ford Mine, one-half mile from San Andreas. The mine was formerly opened to a depth of 700 feet. The present company unwatered the workings to the second level, after cleaning out 60 feet of caved shaft. They report new work underground consisting of 182 feet west and 190 feet east on the 100 level. On this level on the west they found a vein on which they drifted 60 feet and crosscut 44 feet in vein matter. A portion 12 feet wide in the center of this is said to assay well. Some of the quartz seen in place by the writer shows free gold. This vein is a stringer lead in black and greenish schist, with tale on the walls. It strikes about N. 18° W. and in one part of the west workings dips west on account of local faulting, the normal dip being east about 62°. The fault gouge, where one portion of vein was thrust over the other, can be seen. The hanging wall part of the mine as explored in the east crosscut, shows a vein six feet wide, well mineralized with pyrite, 100 feet east of the shaft. It dips east about 50 degrees and is very tight with no gouge. In the next 100 feet, this crosscut shows several tale gouges, and an intrusive rock now changed partly to tale cuts off stringers coming in from the northwest.

The new company claims to have spent $18,000 to October 1, 1923. They have built 2 miles of electric line and have installed motors for the hoist, pump and compressor. Four men were employed when

visited November 9.

Bullion Hill Mining Co. (Bibl. Preliminary Report 8, Jan. 1922.) This company suspended work about the middle of the year at the Washington Mine, six miles north of Murphy. Time and money that should have been spent in the development of a promising property

were wasted in litigation between members of the company, and work stopped, according to local report, when ore above the adit level had been removed. The owner has taken steps to recover the property.

Golden Eagle Development Co. R. C. Johnson, 453 Frederick Street, San Francisco, has a lease and option to purchase Golden Eagle Claim from the owners, and has located three other claims adjoining, and has formed a stock company to work them. Claims are a mile east of Sheep Ranch, in the southwest quarter of Sec. 9, T. 4 N.; R. 14 E. Equipment includes a small steam engine and hoist, headframe, and shed.

An old shaft 70 feet deep near the center of Golden Eagle claim had been cleaned out and deepened 30 feet up to November 3. The vein shows a wide outcrop near the shaft but can not be traced far on the strike. It strikes northeast. At 100 feet depth the shaft shows a decomposed dike about 20 inches wide with five inches of bluish quartz on the hanging wall and 3 or 4 inches of quartz on the footwall. It is possible the shaft is in the hanging wall of the main vein and that a crosscut will be needed to reach the vein.

Jolly Tar Mining Company. Based on a lease and option to buy a patented quartz claim of the same name in Sec. 28, T. 3 N.; R. 13 E.; one-half mile from Altaville on the Esmeralda road.

When visited November 9 the property was idle and deserted and the shaft more than half full of water. One of the owners stated the shaft had been sunk about 325 feet and that during recent work a sudden flow of water had been opened, forcing the men out until a larger pump can be installed. The dump shows that all the work has been done in blocky amphibolite schist with meager seams of calcite and quartz. Crosscutting to the east is planned.

Morgan and Melones Mines. These mines are now operated as a unit by Carson Hill Gold Mines, Inc., William J. Loring, general manager. The group also includes Calaveras Consolidated Mine. The combined properties with their central milling plant, which has a monthly capacity of over 15,000 tons, are the only producing mines on the Mother Lode in the county at this time, and rank among the five largest gold quartz mines in the state as regards both gold output and tonnage handled.

The story of the rejuvenation of the Morgan Mine by Loring after an idleness of 20 years, and the purchase and successful operation of the Melones Mine by him in conjunction with the Morgan after the Melones Mining Company had closed their mine down on account of high costs, is an instructive illustration of the possibilities of deep mining on the Mother Lode.

Ore is being milled from the flat veins of the Morgan Mine and from the deep workings of the Melones Mine. The Melones workings have reached an inclined depth of 4268 feet, measured from the apex on New Year Claim. The lower levels of Melones Mine are reached by a crosscut and new 3 compartment shaft. The later developments in this mine showed again that good ore recurs in depth on this lode if finances permit sinking and exploration at sufficient depth.

The annual production for 1923 is expected to be about as in the past.