The property of the Yellow Jacket mine includes three patented claims, the Yellow Jacket, Colorado, and Colorado Extension, having a total area of 37.7 acres. The group adjoins the Eldorado property on the south at Kanaka Creek and extends northwestward across the point of the ridge between Kanaka Creek and the North Fork, adjoining the Osceola claim near the North Fork. The mine was owned in 1925 by R. W. Gillespie, who was also the owner of the adjoining Osceola mine. It was not being operated at the time of visit. The production has been small. A little high-grade ore, possibly about $8,000 worth, was obtained in 1924 from the Colorado vein, which in the Yellow Jacket workings has been explored by a 1,000-foot drift and several raises. It is said that about $20,000 was produced many years ago from sluicing on the outcrop of the Yellow Jacket vein. The old workings on the Colorado and Colorado Extension claims are also reported to have yielded a little high-grade ore.

   The country rock is chiefly amphibolite schist of the Tightner formation showing the usual variety of amphibolite, amphibolite schist, and slaty schist. A small bed of coarsely crystalline limestone, possibly the same as that cropping out at the portal of the Eldorado tunnel, is cut in the eastern crosscut of the Yellow Jacket tunnel. In places the amphibolite is replaced by quartz along rather indefinite zones parallel to the schistosity. The Tightner formation is cut by several small dikes of serpentine and gabbro roughly parallel to the schistosity. Where serpentine and gabbro are in contact there is an apparent gradation between them.

   The Yellow Jacket vein, which forms the northward extension of the Eldorado, follows a thrust fault with a probable displacement of not over 100 feet, though the data for measurement, based on the apparent off-set of a small gabbro dike, are not adequate for a close estimate. It is not well defined and is faulted by one or more faults which dip steeply to the northeast.

   The Colorado vein, which is essentially continuous with the Bullion vein of the Eldorado mine, to the south, and the Osceola vein, to the north, probably follows a normal fault. The displacement here may be more than 100 feet measured along the dip, but this estimate depends on the apparent offset of a serpentine dike which is cut obliquely by the vein. The small westward-dipping vein appears to lie in the plane of a reverse fault of small throw and faults the fissure followed by the Colorado vein, though the quartz filling of the two is contemporaneous.

   The principal workings start from an adit whose portal is at the south end of the Yellow Jacket claim, near Kanaka Creek. Here for about 300 feet a drift follows the Yellow Jacket vein, but it is not as well defined as in its southern continuation, the Eldorado vein, and at its north end it appears to fade out into several different slips with little or no quartz. A crosscut extending 850 feet to the southwest reaches the Colorado vein, which has been followed by a drift for about 1,000 feet, almost the entire length of the Colorado Extension claim. The vein varies somewhat in strike (average N. 20 W.) and dip (average 45 E.) but is much more regular than the Eldorado. In general the dip is steepest in the upper workings. The maximum width is 10 feet, but over part of the distance quartz is lacking entirely, though a well marked slip indicates the course of the vein. Post-mineral thrusts within the vein were noted in places. The grooving on the fault planes is very regular, the strike varying only a few degrees to the north and south of west.

   The upper tunnels on the Colorado Extension claim show a vein of similar character, though the proportion of the quartz is rather less than in the lower drift. The dip is to the east and is rather steep (54) in the southern part but flattens greatly (27) to the north The uppermost of the three tunnels follows a minor northerly vein which has an average dip of 65 W. and probably belongs to the same group of faults which cut the Sixteen to One vein between the 1,800 and 2,100 foot levels. The middle tunnel shows the major eastward-dipping vein cut off by a shear zone carrying some quartz, which is apparently the continuation of the westward-dipping vein of the upper tunnel. Near this point a small westward-dipping vein joins the major vein without displacement of the vein filling.

   The small shoot of high-grade ore mined on the lower level was obtained from the north end of the principal swell in the vein, about 100 feet north of the crosscut. Here the dip (55) is somewhat steeper than the average. North of this point the quartz is cut off by heavy gouge walls, at a small angle to the strike. A small amount of high-grade ore was also found 100 feet farther north, where quartz comes in again. The high-grade ore was associated with fractured ribbon quartz.


Read about the Gold Strike at the Yellow Jacket - 1952

Excerpts from: Whispers on the Winds (about the Yellow Jacket mine)


Gold Veins through Alleghany Claims 1925.






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