Salt Lake Mining Review | 1914-10-15 | Page 9 | Rainbow Mine of Gilson Asphaltum Co.

rainbow ral abow mine mi ne of gilson gl son asphaltum co by D FORD the rainbow mine owned and operated by the gilson asphaltum company is situated in the eastern part of uintah county utah about eight miles northwest of dragon and some three miles south of watson the property is only a f few ew miles 7 4 iz X a t Z i a en av sacked backed gilsonite at the rainbow mine from the state line the gilsonite vein extends some distance across the line into colorado but is too narrow there to be worked economically previous to february lath 1908 the I 1 dragon mine had been the largest producer of gilsonite but on this date an explosion occurred killing two miners causing thousands of dollars of damage and setting fire to the mine after considerable expense and several months delay the mine was j arl CT A whip hoist at the rainbow mine again put in operation though the fire was never completely extinguished at different times the smoldering fire threatened to put a stop to the work but it was not until october 1912 that it burst into flames again and caused a shutdown shut down of two months an expensive plant had been built here the ore was mined by air drills and hauled by compressed air locomotives water lines were laid throughout the mine and it was sprinkled regularly A return air way was driven twenty five feet above the main lip i 7 OL S pik i cm Y 7 burned out vein at the dragon dracon mine tunnel and a ten foot centrifugal fan furnished air hobbell safety lamps were used the main tunnel was three thousand feet long and the production averaged over one thousand tons per month the only nearby near by source of water in the locality was in evacuation creek but this was strongly impregnated with alkali rendering it unfit for domestic purposes or use in the power house in the attempt to obtain water two wells were sunk to a depth of several hundred feet but produced only small amounts of sulphur water which was used for sprinkling purposes all of the water was brought in by the train a distance of twelve miles this was always a source of considerable expense and the only coal available was of poor quality and high priced making the operation of the power house very costly in the spring of 1911 it was decided to abandon this property and after considerable prospecting a site was selected for a new mine this was on the rainbow vein eight miles to the northwest two shafts showed the vein to have a width of ten feet and a sufficient depth to produce ore for several years during this summer the uintah railway was extended nine miles down evacuation creek and the new town of watson built at the terminus from here a four mile line runs to the mine there is a raise of feet in this distance necessitating a 5 per cent grade for the greater part of the way the elevation of rainbow is feet the uintah railway 6 the uintah railway was built about ten years ago principally for hauling gilsonite it is now sixty three miles long and connects with the denver rio grand at mack colorado it is a marvel for its steep grades and sharp curves crossing baxter pass the train travels twenty four miles to cover an actual distance of six three and four per cent grades abound there are several miles of five per cent grade and an unbroken five mile stretch of seven and one half per cent the sharpest curves are 66 degrees early in the spring of 1912 the buildings at the dragan mine were dismantled and all that were necessary were rebuilt at rainbow in view of the high cost of steam power it was decided not to erect a power house at the new mine this necessitated a rather crude method of mining but it has proven much cheaper than that employed at the dragon mine the new mine is situated on the divide between evacuation creek and asphalt wash overlooking a country that is dry and barren greatly eroded and deeply cut by immense canyons the surrounding country is entirely sedimentary in character belonging to the bridger formation and consists of alternating layers of shale and sand stone the strata have a strike of approximately southwest and northeast and dip about five degrees to the northwest cliffs formed by the sandstone stand out in striking prominence forming peculiar peaks and spires to the north and west the uintah and wasatch ranges can be seen and the Book cliffs are only a few miles to the south the vegetation is principally greasewood and sagebrush the hilltops are usually covered with a sprinkling of scraggly cedars and pinion though these quickly disappear a few miles to the north and west the near source of supply of mining timbers is in the region ot baftir pass some thirty miles distant where the uintah railway crosses the book cliffs at an elevation of feet veins of gilsonite this section of uintah county is noted for the gilsonite veins which occur here in great profusion the veins are nearly parallel run in a northwesterly direction and are practically vertical the largest vein is the cowboy several miles to the north of rainbow which has a maximum width of eighteen feet and for four miles is not less than twelve feet wide its total length is about ten miles this vein has been prospected to a depth of feet but has never produced ore of shipping qualities there are other veins of great width in this region which are not worked on account of their distance from the railway the gilson company owns ten claims on the rainbow vein two of which are worked at present and plans are made tor for working three more the average width of the present workings is about ten feet although in some places it is fifteen feet wide and in other places the walls have pinched or horses have narrowed the vein to a small width in only one place has it become too narrow to work economically gilsonite Is the trade name gilsonite is the trade name for the mineral which belongs in the same group as etc all of which are found to the west of uintah county gilsonite is a black tarry looking substance with a brilliant luster it is exceedingly brittle and produces clouds of chocolate brown dust which is very penetrating to the skin and lungs it is readily softened by the heat of the body and adheres to the skin like a coat of paint it is insoluble in water and is most easily removed by a liberal use of coal oil its composition is approximately 88 per cent carbon and it 11 per cent hydrogen with traces of sulphur it occurs in the vein in a solid homogeneous mass where subject to agencies it losses its brilliant luster and assumes a dead black color at places it has a fine columnar structure at right angles to the walls this is called pencil ore and is frequently found on one or both sides of the vein in a layer several inches thick though sometimes the entire vein may be this kind of ore as is the case with the cowboy vein none of this ore has as yet been found at the rainbow mine the veins outcrop on the hilltops but in the valleys is often covered to a depth of twelve or fifteen feet the surface ore melts at 1 degrees F and is use principally in the manufacture of roofing beneath the white label or surface ore and at depths depending on the effects of weathering is found the blue label ore this has a more brilliant luster than the surface ore contains less foreign matter and breaks with a fracture below the blue label ore and generally at a depth not exceeding fifty feet is found the highest grade of ore this is called select and is used in making high grade paints vart bishes electrical insulation etc methods of mining there is such a small demand for the poorer qualities of ore that much of these grades are left in the ground at rainbow the method of mining is as follows on account of the inflammable nature of this material no attempt is made to use explosives it is not hard but is very ery brittle and a sharp pick can be driven an inch or two into it and when it is trenched near the wall the middle part quickly expands and breaks to pieces the larger lumps are then easily broken by hitting with the flat side of the pick the ore in the vein at the higher points was entirely removed a track was placed on through the vein and carried across the smaller valleys on fills and trestles from this level shafts are sunk feet apart they are about twenty feet deep and are sunk to the select ore when drifts are driven in each direction and all the shafts are connected below this drift all the ore is mined by underhand all the mining is done by contract which includes putting the ore in sacks holding approximately pounds of gilsonite three miners generally work in one shaft fifty feet being ample room for one man to work and for storing some fifty or sixty sacks of ore five tons of ore a day is the average amount produced by each miner sufficient light and ventilation is furnished by these shafts to work to a depth of feet the mine track is laid as near as possible to one side of the vein allowing room for the hoisting of sacks between the other wall and the track two sacks are hoisted at one time by a horse but at the deeper holes three sacks are hoisted by a team when the shafts are not more than eighty feet from the track a derrick is used for hoisting and the sacks are swung directly on to the railway cars at other places the sacks are placed on small trucks and crammed out of the mine by hand the greatest production to date has been 2700 tons per month in 1913 addi dional side tracks and switches were built so that this production can be greatly increased if necessary I 1 the timbering is very simple the ore ord which is left in place as pillars between the shafts or around the horses that are occasionally casio nally encountered in the vein must be securely timbered the pressure of the kwall wall and the heat of the summer days will pause cause this ore to slough out rapidly I 1 the walls are often quite irregular or stepped varying from a few inches zo to several feet an irregularity on one wall generally has a corresponding correspond mg one on the J opposite wall these must be firmly tim bared even though they appear absolutely j I 1 solid at the time of being exposed as othere there is invariably a small amount of gil bonite behind which will allow the rock to work loose the only method of entering the mine is by means of ladders which are securely enclosed with strong wi wire F netting surface improvements the buildings consists of mine office boarding house bunk house fourteen dwellings with accommodations for seventeen families and a school house which is fre used for the purpose of entertainment and instruction other buildings consist of warehouse barns oil house and blacksmith shop the water brought in by train is emptied into a cistern located above the town and is piped to the different houses and watering places in addition to the rainbow mine the gilson asphaltum company operates the big bonanza mine this is located on the bonanza vein about twelve miles north of watson A similar method of mining is employed here but as the ore must be teamed to the railway only small amounts are mined