Located about 25 miles west-northwest of Helena near the town of Avon is the Ophir District. The district lies in two counties, Powell and Lewis and Clark, with the upper portions of the major drainages in Lewis and Clark County. The Powell County portion of the district and the western half of the district in Lewis and Clark County are accessed by road from Avon. This portion of the district was on the Northern Pacific Railway. The eastern portions of the district is accessed from Helena through Marysville.
Limestone, shale and quartzite of lower Paleozoic age are the dominant geologic materials in the area. In the Avon Valley there are also deposits of clay, sand and volcanic ash belonging to the group known as the Tertiary "lake beds". Along the principal streams carved in the Tertiary beds are gravels of varying thickness derived from the adjacent mountains; these gravels contain the placer deposits. The lodes which contain gold and gold-silver ore occur primarily in the limestone. The ore bodies are irregular and some can be described as cylinders or pipes. They contain chiefly pyrite or chalcopyrite or their oxidized forms in a gangue of quartz or metamorphic silicates.
Placer mines were active in the district in the 1860s and 1870s and Blackfoot City, later renamed Ophir, was a thriving mining camp. Ophir Gulch was placer mined for eight miles while Carpenter and Snowshoe Gulches were placered several more miles. Among the richest deposits of placer gold were the Prairie Bar and Carpenter Bar. On the McKay Claim in Deadwood Gulch, which is a tributary of Snowshoe Gulch, a miner named Ed Risson found Montana's largest gold nugget. The nugget was reported at the time to be worth $3,280. It is estimated that the placers produced around $3.5 million in gold in the early years (Pardee and Schrader 1933).
After the initial placer era, activity diminished but beginning in the late 1880s individual lode mines began to be developed. Most of these mines were located in southern Powell County, the southern portion of the district, but the Ajax mine, located in 1888, was on Cave Creek in Lewis and Clark County. In 1900 the Victory mine, just below the Ajax and also in Lewis and Clark County, was discovered. By 1912, the Victory mine had produced $40,000 in gold and silver, some of which was worked in a mill on the site. The 20-ton Victory Mill was an amalgamation and concentration operation that had a 10 ft Lane mill and six Frue vanners (Hall 1912; Pardee and Schrader 1933).
BOUNDARIES OF THE DISTRICT
As noted above, the Ophir mining district shown on Figure 1, is actually in both Lewis and Clark and Powell counties. Access to the Powell County mines and those in the western part of Lewis and Clark County is by road from Avon. Those in the eastern part of Lewis and Clark County, and particularly in the upper Dog Creek drainage, are accessed through Marysville and are included in the Marysville mining district by all historic sources. The most significant and the most southern of these mines, the Bald Butte, appears frequently in the mining literature as being in the Marysville district. Figure 1 shows the Ophir mining district as defined by Pardee and Schrader (1933) and Sahinen (1935) as including the area in Powell as well as the small section in Lewis and Clark counties.
HISTORIES OF SELECTED MINES
Most of the mines in the Lewis and Clark County portion of the Ophir district are generally included as part of the Marysville district. The Ajax and Victory are two of the few lode mines in the area that actually went into production.
The Ajax mine is located about three miles northeast of Ophir on Cave Creek, a tributary of Ophir Creek. It was opened in 1888 and operated until 1912. The mine was worked to a depth of only 70 ft, but produced $48,000 in gold ore. The mine worked a "iron pipe" in Paleozoic limestone and the ore was valued as high as $100 per ton.
The Victory mine, located two miles above Ophir on the west side of Ophir Creek, was discovered in 1900 and developed beginning in 1906. The mine development included a 175 ft shaft, an adit and a 90 ft winze. The mine was active until 1912 when work was halted due to excessive ground water. The gold-silver ore, quartz with pyrite and chalcopyrite, was valued as high as $40 to $100 per ton. Some of the ore was shipped, but some was worked at mill at the site. The waste dump of the mine and the mill tailings were later reworked using the cyanide process. All told, the mine is reported to have produced $40,000 by 1912. Some additional production was achieved in 1917, 1918 and 1930.
Pardee, Joseph Thomas and F. C. Schrader
1933 "Metalliferous Deposits of the Greater Helena Mining Region, Montana", US. Geological Survey Bulletin #842, reprint of article in Mining Truth, Vol. 14, No. 10.
1935 "Mining Districts of Montana" Thesis. Montana School of Mines.
Swallow, G. C., J. B. Trevarthen and Jacob Oliver
1891 Reports of Inspectors of Mines, State of Montana, year ending November, 1890. Journal Publishing Company, Helena.