The Largest well known unpatented mining property in the Silver City Mining District. Reportedly produced 4 OPT Gold and 50 OPT Silver. Over 4000 feet of workings.
The Great Western mine is named for the Mining Company which originally developed it, Great Western Mines Co. The mine is located on the western slope of French Gulch, near the head of the Gulch. This being in the French (Silver City) Mining District, in Owyhee County, Idaho. The mining claims are roughly 1.7 air miles from Silver City in the heart of the Silver City Mines.
The mine is one of the larger known workings that is not privately held. The Mine tapped the eastern extensions of the famously rich Oro Fino and Golden Chariot veins which were worked exclusively for gold deposits. Despite appearances, the mine gives access to over 4000’ of drift workings cut on the Oro Fino vein and other smaller gold veins that were defined. A good history prior to 1950 details the workings and development of the property. Despite the name, the mines and the town of Silver City produced substantial amounts of gold. Gold dwarfed the silver output of the area, not necessarily due to the availability, moreover due to the value of gold over silver.
A single adit portal accesses the entirety of the workings. The mine was reported in 1926 to be developed to just over 4000’ addressing the Oro Fino vein which carried values averaging 4 oz/T in gold and 50 oz/T in silver.
A large number of concrete foundations for houses, winches, and engines are a testament to the amount of development that was done on the claims.
The Mine is located in a high elevation relative to the area and will likely see substantial snowpack for at least 3 months out of the year (Dec.-Feb).
Location and Access:
Located 90 miles outside of Nampa, Idaho in Owyhee county. Good 4wd access for short wheel base vehicles. Long wheel base vehicles will have some technical spots on the 4WD road.
The Great Western Mining Claim is located east of Silver City in the French (Silver City) Mining District. Based on the Oro Fino vein, of which the Oro Fino Mine and Oro Fino group was defined in 1863. From 1863 to 1890, the Oro Fino group of mines (around the Oro Fino Mine but not including the Oro Fino) produced seven (7) Million dollars in gold and silver values. Historically gold values are far higher than silver values.
A long road winds up the mountain to the Great Western Mine. This road is in relatively good condition and could be traversed by most any high clearance 4WD or UTV. Vehicles with a long wheel base or trailers will have some additional challenges with dips and steep ascents.
The site was reclaimed by the Forest Service in 2015-2016. The original wooden adit portal was carved out in favor of a culvert and a gate. The culvert is a valuable addition to the claim as it provides a stable point of entry to the workings.
The mine is discharging a small amount of water that was not tested, but is overall clear and shows little visible contamination. The mine itself has 6-8 inches of water in the entrance, this from the culverting and build up in the adit which is allowing the water to pool in the mine instead of flowing out as designed.
In 1924 an assessment of the mine was made by the Idaho Bureau of Mines.
The description is as follows:
“The property of the Great Western Mines Co. is located On Sinker Creek drainage about a mile distant and nearly due north from the summit of War Eagle Mountain. The property comprises six and a fraction unpatented claims; five of which are held under lease and bond. The property was acquired by the present operators in 1920, and furnished with an electrically driven 10 by 10 in. compressor. pneumatic drills, and complete equipment for efficient prospecting. The underground development has been on one level only, and through an adit crosscut 1,067 feet long. A drift which turns southward about 100 feet from the portal, reaches the probable extension of the Oro Fino vein about 800 feet to the south and follows it southward more than 1600 feet. A second drift is turned near the face of the adit and has been prospected 600 feet along portions of two other veins of opposite dips. A plat of these workings is reproduced, and the multiple faulting shown thereon has been referred to previously as a 1 ½ to 2 inch stringer of massive quartz at the west wall of the vein breccia has yielded secimen gold ore near the south end of the easterly drift. Fragments of "drag ore" were also encountered in the gouge filling of the fault zone which strikes westward across the vein about 1,800 feet south of the adit. Pyritized quartz. is found in bunches scattered through all the vein segments developed. A small body of ore has been extracted from a shallow shaft on the Chapman claim, above the southern extremity of the Oro Fino vein drift, but the lower development found no continuation of it.
At present the west drift is being driven beneath a second body of surface ore opened by an adit drift about 1,150 feet southwest of the Great Western adit portal. It has not yet, however, reached its objective.”
In essence, with this information, the general trending of the vein and the design of the drift workings, at least in 1924 can be defined and mapped out on the surface.
The water dumping from the adit was clear but washed over quartz, oxidized iron and some pyrites. Surveyors saw no visible gold in the run off, which is to be expected after such a recent reclamation project which no doubt changed the structure of the site and compromised the historical integrity.
The waste dumps on the claim show quartz, some lead and silver, and iron. There is an estimated 125k Tons of waste dump outside of the main adit. This is a little less than would be expected of 4000’ of drifting and undefined stoping efforts, however, the dumps are on a steep drainage and may have been washed by erosion over the past 70 years.
The property is set on a good flat and extends far up the gulch but this is not apparent on the ground. The underground development does not appear to have any surface or vents and there is no indication of it in any way. The property extends up to the patent property lines of the Oro Fino property which is noted as being fully worked out and completely shuttered and abandoned.
Contact Gold Rush Expeditions for a GRMP43 Technical mine report that details the geology of the Great Western Claims.
Contact Gold Rush Expeditions for a GRMP43 Technical mine report that details the history of the Great Western Claims.
Contact Jason at Gold Rush Expeditions with questions, to obtain a copy of the GRMP-43 report or more information.