Development of the Gold Belt along the South Fork of the Coeur d’Alene River began with Tom Irwin and Andrew Prichard several years before gold was discovered in the North Fork or Murray District. Irwin staked a lode claim in 1878 on a quartz vein just south of the Mullan Road between the present day towns of Kellogg and Osburn. Prichard was working in the same area, but was looking for placer gold, just north of the Mullan Road and about 1 ½ miles east of Irwin’s claim. The Mullan military road, built in 1865, provided better access to the South Fork area while the North Fork area was still isolated.
The site of Irwin’s prospecting work is thought to be a narrow, high grade quartz vein, now called the High Grade vein, which is only 12 to 18 inches wide but contains visible grains of gold. A caved, inclined shaft on the vein which dips about 65 degrees to the west was observed in this location when New Jersey Mining Company (NJMC) personnel first prospected the area in the mid-1980s. The size of the nearby dump fits historic descriptions of the Irwin shaft. Several other prospect pits and adits are also in the area.
Today, the site of “Miners Cabins” is not known with certainty but was likely located near a trail which leads from the South Fork to a flat ridge just to the south where the gold showings are located. The slough along the old Mullan Road in this area is named Miners Slough, providing further evidence of the probable location. Construction of the Wallace Line of the Oregon Railroad and Navigation Co. in the late-1800s probably destroyed the Miners Cabins site.
Just south of the High Grade vein is the larger but lower grade Coleman quartz vein, which was the subject of an intensive development effort between 1900 and 1910 by the New Jersey Gold Mining and Milling Co., incorporated in Washington in 1898. A company brochure dated May 1903 describes the Coleman vein and plans to build a mill, reporting that 1,455 feet of tunnel was completed along with 183 feet of shaft with 100,000 tons of ore developed. The vein is described as “40 feet wide by 600 feet long” with assays reported to be near one ounce per ton.
The company constructed the mill along with an 8,300-foot flume from Big Creek to supply water and to generate electric power. A camp for the miners was constructed in Gold Run Gulch. The mill was constructed at the mouth of Gold Run Gulch where the present New Jersey mill is now located. A purchase order for a “10 Stamp Mill, Two New Standard Concentrators, Light Plant, with Power for 40 Stamps and Eight Concentrators” from the Hammond Manufacturing Company, Inc. is included in the 1903 brochure. A surface tramway was also built from the mill to the Keyhole Tunnel which is the mid-level crosscut to the Coleman vein.
The Coleman group of claims was surveyed for patent in 1904 and finally patented after a long bureaucratic process in 1911. Other property in the area was transferred to private ownership by homesteading or outright purchase. The High Grade prospect is still on Public Lands.
After development work subsided in the early part of the 20th century, there was a long period of inactivity in the South Fork Gold Belt. In the mid-1980s, the founders of NJMC commenced prospecting for gold in the South Fork. By this time most geologists in the Coeur d’Alene Mining District had forgotten that gold occurs along the South Fork because the district is mainly known for silver, lead, and zinc.
Mine Systems Design acquired exploration rights to the High Grade and Coleman veins along with land to the east under the Shoshone Golf Course from Gold Run Gulch Mining Company and William Zanetti. A joint venture was formed with Mine Systems Design, Plainview Mining Company, Silver Trend Mining Company, and two other parties. The joint venture built a gravity mill, now the expanded New Jersey Mill, at the mouth of Gold Run Gulch. A new corporation, NJMC, was formed in 1996 from the joint venture, followed by a reverse merger into Plainview.
NJMC subsequently dozed the surface near the Irwin shaft to expose the vein and adjacent altered wallrock. An induced polarization-resistivity survey showed the potential for sulfides along with quartz down dip from the Irwin shaft. Core drilling began in 2001, with the first hole intercepting a silicified zone from 87 to 95 meters with gold assays up to 2.1 grams per tonne (gpt) and a second zone from 104 to 114 meters with gold assays up to 2.9 gpt. Another hole drilled between the Irwin shaft and the first hole, intercepted the High Grade vein at a depth of 95 meters, assaying 17 gpt gold over a 0.55-meter width.
Getting back to Tom Irwin, he reportedly sold his claim in the 1880s to a man named Goldsmith from Kentucky for $50,000, and then probably left North Idaho a rich man. We at NJMC are privileged to carry on Irwin’s and Prichard’s pursuit of gold exploration and mining in the heart of one of the richest and most prolific mining districts on earth, the Coeur d’Alene.