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Willoughby: Finding silver not exactly a science

My father spent over 20 years underground deciphering the mysteries of where silver could be found. As a young man he grilled the old-timers on the subject, sorting out their personal experience from the rumors.

The ore deposition of the Little Annie and Midnight mines was different than the town side of Aspen Mountain and the Smuggler Mountain mines. He also had geology reports to peruse, although he once told me that geologists were not good at giving specific locations but once found, they could explain why silver was there. Extensive experience in a section of the vast Aspen mineral lode was the best guide.

The following analogy might help you understand the complications and difficulty in searching for Aspen silver.



Map showing the complicated geology of the Midnight Mine.
Willoughby collection

Picture a truck loaded with 5-pound bags of flour stacked to the top of the bed but with the tailgate missing. The truck is making deliveries on Red Mountain going up the main road but also taking trips along the side streets. On the steep grade a few bags fall out of the truck. Some split open when they land, spewing flour all over the road; others remain intact, but some are run over by other vehicles, squishing them into a pancake shape.

There are chuck holes and every time the truck hits one, bags fall off. On the way up the driver brakes for a deer and a large pile falls out. Every time he comes back to the main road he slams on the brake at the stop sign and a few bags drop. On the side streets the driver stops, gets in the back, and throws the bags of flour into the yards of some of the houses, puts others in the mailboxes, and for others with big orders stacks them at the end of the driveway.




A few hours later a snowstorm moves in, covering everything with 2 feet of snow. When spring comes, melting snow dissolves the paper bags and washes the flour into rivulets heading in all directions. The lower on the mountain the more flour accumulates. Instead of patching the chuckholes, the main road is repaved, covering the flour. The water company digs new trenches truncating the layers.

Then think of someone tasked with finding all of the lost flour and you get some idea of what miners faced. Just add that a windstorm blew in a hundred feet of dirt to cover everything and to find the flour you had to dig underground and look in the dark.

Your most important guide would be to follow the pavement. For Aspen’s silver they followed fault lines, with the main fault being the Castle Creek Fault that went from Ashcroft to Red Mountain and then followed all of the many faults that transected it. The most silver was found where they intersected.

You have to think three-dimensionally. There are geologic layers, so think of the asphalt as a geologic layer; Aspen and Leadville silver was found near the Leadville Limestone formation. The layers were horizontal when formed but tilted later. The tilt was fairly predictable in Aspen, so it would be like the Red Mountain Road grade, although much steeper. However, think of the bags thrown into the yards away from the asphalt. That happened with silver, too.

The smashed bags give you an idea of another challenge. Silver was found along the fault lines near the limestone in small amounts that were not profitable to mine. Miners would follow the traces hoping it would lead to larger amounts, but if you are tunneling along the asphalt flour traces and you are on one side of the road and the bag that dropped off fell on the other side, you might not find it. There were many tunnels and shafts in Aspen that never produced payable ore.

Water flowing through and over the flour would move it, transform it and redeposit it in other places. That is what happened to Aspen’s silver. In some mines more silver accumulated at the lower levels; in others the lead accumulated at the lower levels.

Finding silver was not just luck; miners, especially experienced ones, deciphered the geologic layers and patterns underground. Small changes in the color or the density of the rock they were tunneling through gave them clues. They knew when they crossed fault lines.

Aspen miners crisscrossed at different levels under the mountains for over 70 years. Did they find all the silver? No.

Tim Willoughby’s family story parallels Aspen’s. He began sharing folklore while teaching Aspen Country Day School and Colorado Mountain College. Now a tourist in his native town, he views it with historical perspective. Reach him at redmtn2@comcast.net.

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