Mines of the Argo
Central City, Colorado

The Glory Hole on Quartz Hill

The Glory Hole on Quartz Hill

More mines than people” should be the nickname of Nevadaville, not that it’s much of a statement; it’s a ghost town. Though, few Instagram tourists who look our across the slopes of Quartz Hill at the dozens of piles of yellow-white tailings (the color is due to the arsenic) know that the greatest mine is not on the hill. It is the hill.

Gallery: Hubert Mine and Nevadaville

Gregory’s Diggings

Quartz Hill is a former volcano, and while it died and the magma in its veins slowly cooled, gold, silver, zinc, and a variety of other valuable minerals were formed and pushed upwards under incredible seismic pressure, thus creating many veins of very rich ore in a very small space.

A detail of Quartz Hill’s claim map in 1917. It was a confusing time. Bastin Hill 1917.

Approximately 1,700,000,000 years after Quartz Hill was formed, 1859 if you want to be picky, a man named John Gregory was on his way to Pike’s Peak when he discovered gold while panning near modern-day Black Hawk. The “Gregory Diggings” were so rich that word spread fast, and soon many towns were founded nearby and hundreds of claims were being staked. Along with the mines were mills, to extract the actual ore from the junk rock (tails), and smelters to melt and refine the ore for shipment, often to Denver’s United States Mint.

Receipts from the Denver Mint for Chain O’ Mines deliveries in the 1930s. From Muchow 1952.

Trams and Tunnels

To move the ore from mine to mill in the mountains, local entrepreneurs built the Gilpin Tramway, a narrow gauge railroad that wound from Black Hawk through Central City, Quartz Hill, Nevadaville, and onto Russel Gulch, another ghost town. Over time, it would expand south and include dozens of sidings. As new mines opened and old ones closed, track would be taken up and moved where it needed to be.

The ore could only be loaded, however, if it was mined, and it could not be mined if the mine was flooded. This is where the Argo Tunnel was crucial to the success of the mines in “The Richest Square Mile on Earth”, a longstanding nickname for the Quartz Hill area. The Argo is the greatest of three historic tunnels mined into the mountain, in addition to the La Crosse Tunnel, Columbia Tunnel, and Quartz Hill Tunnel. In addition to the veins that ran through Quartz Hill, gold deposits also manifested vertically through the hill in a chimney formation, so it could be found almost anywhere under the summit.

Richness and randomness meant every stake on the hill was a gamble, and in a time when everyone seemed to be striking it rich near Central City, many many people decided to take up the pickaxe. Radiating out from the summit were mines with names like ‘The Gold Retort’, ‘The Protection, ‘The Roderick Dhu’, and ‘The Weal-Vor’.

The La Crosse Tunnel cut through the middle of Quartz Hill, a place that became known as ‘The Patch’ because of the tight cluster of small stakes. Visitors can still see the tailings it left behind from Nevadaville. The La Crosse Tunnel was a bit deeper than Quartz Hill Tunnel, being 700 feet below the summit of the hill, and it cut southwest from the north slope and straight through ‘Climax’ and ‘Kinney’. As one can expect, many conflicts erupted over mining claims and ownership of the 40 or so mining claims in and around The Patch. Claims follow the ore, not the outline of the property above. Also, aside from the tunnels mentioned, there were many other underground connections between mine workings, making it almost impossible to distinguish between them.

Chain O’ Mines Era

Number of mines operating in the Central City district, 1910-1952, from a USGS report.

By the mid-1920s, the number of active mines in the area fell from 90 to less than 10, and the even Gilpin Tram had been sold for scrap. Because of a natural process called weathering, gold found nearer the surface tends to be higher quality than that deep below. In other words, around Central City and Nevadaville, as extraction and dewatering costs increased, profit often decreased. Because of the tunnels under Quartz Hill, its mines were less affected than those around it, but by 1925 litigation had stopped many of the operations there. That is, until a crooked dentist from Evanston, Illinois (near Chicago) came to town.

Dr. William Mark Muchow was searching for a source of pale gold for dental applications, and it so happens that ore from The Patch is the perfect shade of yellow. After learning about the legal and operational problems, the dentist began attracting investors and buying-out the feuding mining firms of Quartz Hill. On March 10th, 1928, he had acquired all of the major and minor claims: San Juan, Roderick Dhu, Modock, Kinney, Little Pittsburgh, Hannibal, Gardner, Boston, Gold Retort, Missouri, Oakland, Annie, Protection, Climax, Edinboro, Exterminate, Weal-Vor, and, of course, Patches. The new combined claim, measuring 600 by 1,500 feet, was patented under the playful moniker Chain O’ Mines.

Founding plat of the Chain O’ Mines, showing the claims it subsumed. From Muchow 1952.

The doctor’s big ideas did not stop there. With the summit of Quartz Hill in hand, he derived a plan to methodically cave-in the whole center of his claim into the Quartz Hill Tunnel. Imagine an hour glass with sand draining through it. Ore extracted through the tunnel would be transported to a new processing mill via aerial tram above Central City. The process would turn the top of Quartz Hill into a crater, which earned it a most auspicious name: The Glory Hole.

A diagram showing Muchow’s mine, leading to the creation of the Glory Hole. Muchow 1952.
An ad for Chain O’ Mines tours in Popular Mechanics, 1931.

Ultimately this workflow allowed Chain O’ Mines to process massive volumes or ore relatively cheaply, giving it lasting power. It helped, of course, that the doctor was a masterful salesman—he even planned for a three-story pentagonal tower to be erected as a viewing station for his mine. Though it was never built, it was widely advertised, often in conjunction with Muchow’s Chain O’ Mines Hotel in Central City.

Chain O’ Gold Mills

Even before Dr. Muchow had finished uniting The Patch with its neighbors, his first mill was under construction. However, because of the sheer volume of rock that had to be ground and sorted at the mill, it soon overwhelmed nearby creeks and even buried Central City’s first passenger depot, once operated by Colorado Southern Railway. According to all accounts, it is still there under the tailings, though at one time Muchow promised that it would be exhumed and turned into a museum.

The original Chain O’ Mines Mill in Central City, now demolished. From Denver Public Library.

Citizens rightly became concerned that the tailings being dumped outside of their city was polluting the water and successfully sued Chain O’ Mines in 1934, forcing the mill and much of the mining, to temporarily suspend operations until it was moved to Midwest Valley. If it stood today, it would be at the intersection where Nevadaville Road meets Central City Parkway—the mountain of tailings is obvious.

After raising more funds, principally in the Chicago area, Muchow commissioned a new mill of his own design to be built near the south slope of Quartz Hill in 1948. The 1926 mill was designed by a Denver firm, The Ruth Company, and the dentist believed he could improve on the usual design of gold mills to more efficiently process low-grade ore, and do away with the aerial tram system.

New Mill, 1950

Rather than sending ore from the Quartz Hill Tunnel or La Crosse Tunnel to the top of the gold mill through the air, his new mill would use a 1,500 foot conveyor belt to bring ore from an underground rock crushed below The Patch directly to the mill. When the new mill opened in 1950, Muchow boasted it would eventually be expanded to process 10,000 tons of rock every day, but this was likely an exaggeration to help raise money. For perspective, Argo Mill processed 300 tons daily at its height.

Muchow’s new mill shortly after completion in 1950. It still sits beside Virginia Canyon Road. From Muchow 1952.

In reality, while there was a lot of gold left in the hill, it was quickly becoming unprofitable to remove it because of government price controls, the low grade of the ore, and the rising labor expenses. Indeed, Chain O’ Mines was almost alone at the time, having survived the closing of the Argo Tunnel in 1943 because it retained its own mill and dewatering tunnels. While the Glory Hole did not connect directly to the Argo, mines it was connected to did.

A shallow creek traces Illinois Gulch toward the Chain O’ Mines mill. Ball mills are laid out in the sun.

Post-war mining interest in the area shifted from gold to an element that had recently become more interesting to the world: Uranium. It had been found on the south side of Quartz Hill incidentally along with lead, silver, zinc, and other ore that usually co-occur with gold, but before the end of World War II, it was simply a scientific curiosity. Marie Curie herself used pitchblende collected near the Chain O’ Mines in her radium studies at the turn of the century. Many claims around Central City were pumped and reinvestigated as sources for atomic bomb material. Muchow’s firm was even sued over mining claims by the Gold Uranium Mining Company in 1953 over claims on Mammoth Hill.

These machines circulated water through the powder from the ball mills. Gold and silver is heavier than gravel, so it sinks while the junk rock floats.

Chain O’ Crimes Era

By the 1960s, Chain O’ Mines had all but stopped operations due to growing overhead and dwindling investment. While there was not much capital, the company did have lots of assets it had acquired up over its thirty years, some 300 claims, according to one source. To make ends meet, these excess claims were leased to smaller firms to work independently. If they paid Chain O’ Mines to mill their ore, all the better. The problem was that Chain O’ Mines was not discerning enough of their lessees after Dr. Muchow’s death in 1969 and the claims were the basis of a number of fraud schemes through the 1970s and 1980s, earning it a new local nickname: Chain O’ Crimes.

Frontier Gas is a former (?) gas station chain. Chain O’ mines reused a scrapped sign to mark their mill. Under the paint you can barely make out: GLORY HOLE GOLD MILL.

The last owner of the company was a somewhat unwilling one. Harold Caldwell, who variably called himself the owner or trustee of Chain O’ Mines, depending on whether he was using it as implied collateral or whether it was being sued, lost the property in a bizarre Texan legal battle. Readers interested in that story should read the ‘The Money Pit’ by Richard Flemming of Westword, published in 1994 just as the Gilpin County Sheriff seized the Chain O’ Mines from Caldwell.

Here, the concentrated gold (and silver, and zinc, I would guess) would be loaded into trucks bound for the smelter.


In 2015, a new company filed permits to reopen the former Chain O’ Mines mill to do custom small-batch gold milling. They are rehabilitating and refitting parts of the circa-1950 mill. It seems that gold fever has not yet died on Quartz Hill.

I slid into the mill through the top floor, near where the rock-grinding ball mills were left to rust. I look around, taking in the most intact gold mill I’ve ever explored. Movement attracted my eye to the ceiling, where I found something staring back, a raven was observing me with some interest. It had been a while since I have brushed up on the folklore and mythology, but I took it as a good sign. Leica/Summilux 35/Ektar 100

Gallery: Chain O’ Mines Mill