Alder Creek Mining District, Custer County, Idaho, USA.

The Iron Bog claim is located just west of Iron Bog Creek in the Pioneer Mountains. The road that leads most of the way up to the site is a good, gravel 2wd accessible road with plenty of parking in the nearby Challis National Forest campground. The old road (seen on maps) is barely visible when hiking it, as it is almost completely overgrown with desert brush and doesn’t appear to have been used for decades. But the area has great scenery with the road leading up here following a meandering stream valley. The narrow stream valley is flanked on both sides by mostly grassy and shrub-covered mountains. There is a small stream above the claim, possibly a seasonal creek. There is a small amount of space near the collapsed adit below the shaft. The ground appears largely undisturbed around the shaft, but could probably be modified for staging equipment. The Mines: The claim covers 2 adits, one collapsed and one with a culvert and gate; and 1 shaft uphill from the collapsed adit. The topographic map shows the shaft, and the gated adit only. The collapsed adit is not mapped. Mine entrances, features and types – 2 actual entrances, 1 ore shoot used as an entrance by our exploration team. The entrance to the mine was barely visible from below, when hiking up. A vertical culvert and box iron gate block the entrance. The box iron was reinforced with an iron bar through the middle. Shaft is 50’ including the culvert length. We repelled down through the gate using the gate as a securing point. We found some wooden framework that was barely visible in one or two odd corners. We originally thought it might be railway wood, but the definite incline of the workings and faux paving or mud floor ramp suggest this may have been an extraction point. This would explain why we were not seeing any good ore veins or relevant mineral assemblages in the wall rocks as we are likely above the rocks of interest. General trend of the tunnel/shoot is 130 degrees. Orientation of the host rock is 165/29E with bedding planes that are on the order of several cm’s thick with 1st 10’ of the tunnel’s wall rock being very, very covered in dirt and debris. Average tunnel size is 5’ x 3’ with an average incline of 40 degrees. Porphyritic igneous rocks observed in the area, between these rocks and the oxidized copper above. It’s a shame we couldn’t access more of this mine. As it is, we only saw some of the host rock that surrounded the shaft. If the lower gated adit could have been accessed, it might have shown promising minerals as I think that the mine’s location below the copper oxidation zone is a good fit for being an area of mineral/metal enrichment. There could be significant underground workings in the lower adit. Small adit near stream bed with a lot of gusty, cold air coming from it. The culvert was too narrow to squeeze through.

The Iron Bog claim is just west of Iron Bog Creek in the Pioneer Mountains. It is a short distance west of the major Copper Basin Thrust Fault, and smaller, normal faults, one that dips steeply at 67 degrees runs NE-SW and another N-S trending are through or just near the claim.

Iron Bog Creek Member – Dark gray to grayish black silty mudstone or argillite that weathers light gray to dark gray, and olive-gray; fine-to very coarse-grained lithic sandstone that weathers brownish gray to moderate brown, and lesser dark gray granule- to pebble- conglomerate and minor limestone; lithologies represent channelized conglomerate and sandstone, hummocky sandstone and conglomerate, and graded mudstone lithofacies; included macrofaunal and microfaunal collections indicate a late Mississippian age; thickness exceeds 1,100 m. Soil, bedrock, talus and alluvium – there are many outcrops of limestone and other Mississippian carbonate rocks; some forming prominent cliff faces. Several caves in the cliff faces were observed on the main road while traveling to the claim.

MRDS: no actual data falls on the claim, there is an ‘unnamed prospect’ about 1000’ west, uphill that is reported silver as the only commodity. No further information.

Wall rock is limestone/dolomite with fracture planes that look slightly mineralized with possibly sulfur, iron oxide-hydroxides and tertiary calcium precipitations.

Mineral Resource Database System
http://mrdata.usgs.gov/mrds/show-mrds.php?dep_id=10265202

Approximately 612’ west of claim
http://www.idahogeology.org/Services/MinesAndMinerals/Search/Details.asp?SequenceNumber=IF0114

The Alder Creek district, also known as the Mackay or White Knob District, is in southeastern Custer County near Mackay. Ores rich in copper and gold were discovered in this district in 1884, after the rich lead-silver discoveries at Nicholia to the northeast at the site of the district’s chief mine, the Empire (Ross, 1930a). After many failures to produce copper and after the expenditure of about $3 million, success was finally achieved in 1905 (Umpleby, 1917,), and the mine remained active through 1929. Sporadic production was also reported from 1940 through 1951. Mining resumed in 1957 continued through 1959.

From 1884 to 1913 the Empire produced about $100,000 (about 5,000 ounces) in byproduct gold (Umpleby, 1917). The Empire and Horseshoe mines produced 24,710 ounces from 1912 through 1928 (Ross, 1930a), and the district produced 3,770 ounces from 1939 through 1959. Total gold production for the district through 1959 was about 33,500 ounces.

General District Information:
The district is underlain by folded Paleozoic sedimentary rocks, intrusive granitic and monzonitic rocks, and volcanic rocks of the Challis Volcanics. The Paleozoic rocks are mostly thick-bedded dolomitic limestone containing Mississippian fossils (Ross, 1930a). In the Empire mine area the limestone is intruded by a large mass of granitic rocks and by a swarm of porphyritic dikes that follow a broad zone of regional faulting.

Ore deposits in the district are largely of the contact-metamorphic type and are along the limestone-granite contact. Some ore bodies of the Empire deposit are in large blocks of limestone isolated well within the granite (Umpleby, 1917). The primary ores contain intergrowths of garnet and chalcopyrite and subordinate amounts of pyroxene, pyrite, and pyrrhotite. Oxidized ores, which were highly productive, contain a mixture of chrysocolla, azurite, malachite, and cuprite. Secondary copper sulfides are rare (Umpleby, 1917).