Broken Boot History
Olaf Seim and James Nelson came to the Black Hills and dug a mine just outside Deadwood in 1878. Known simply as Seim’s Mine, it produced about 15,000 ounces of gold over a period of 26 years.
Gold wasn’t the only metal Seim and Nelson found in their mine. They also found plenty of iron pyrite, or fool’s gold. Fortunately for the miners, iron pyrite was in demand. Since it could be used to make sulfuric acid, which was used in the processing of real gold, the miners could get decent money for iron pyrite. The mine made more profit from selling fool’s gold than they did real gold.
Eventually even the iron pyrite wasn’t enough to support the mine. It closed in 1904, only to reopen briefly in 1917. With World War I raging, demand was high for iron and sulfur – crucial components of gunpowder – and Sein’s Mine had enough to become profitable again.
When the war ended in 1918, so did the mine’s lease on life. Seim’s Mine sat vacant for thirty-six years.
In 1954, a group of Deadwood businessmen got together and approached Olaf Seim's daughter, Mrs. Seima Hebert and her husband John. Seima was Olaf's only living heir and current owner of the mine. The businessmen wanted to repair the mine and re-open it as a tourist attraction. Seima and John decided to lease it to the businessmen. The Broken Boot has been giving tours to visitors ever since. In fact, the Broken Boot has operated longer and more successfully as a visitor attraction than it did as a working mine.
Local Geology
The Black Hills are the farthest east outlier of the Rocky Mountain system with which they connect structurally by the Laramie mountains to the south. Physiographically they are not hills but mountains. The average elevation of surrounding plains is about 3000 feet while Harney Peak reaches an elevation of 7242 and other peaks in various parts of the region reach 6500 feet. Nearby Terry Peak attains an altitude of 7071.
The Black Hills were formed by a domical uplift at the end of the Cretaceous which on erosion exposed all of the Cretaceous and older formations down to the pre-Cambrian complex.
The Deadwood Formation consists of a basal conglomerate and buff sandstones, overlain a sequence of by grey-green shales, carbonate rocks, and glauconitic quartzose sandstones. The Deadwood conglomerates contained significant quantities of gold in the Black Hills.
In most areas the sediments of the Deadwood Formation were deposited in near shore, shallow water environments as an ancient sea advanced across the exposed and weathered landscape of Precambrian rocks.
Mine Terms
Stopes
Stopes are large, underground rooms from which ore is removed. They are formed when miners drill numerous holes into the rock wall, called the "working face". These holes are then loaded with explosives and detonated. The blast breaks the working face and rock into pieces small enough to be loaded into mine cars and carried from the mine.
Drifts
A horizontal passageway is called a "drift". Drifts vary in height and width from as little as three feet to those large enough to accommodate an oversized ore truck.
Adit
Entry into underground mines are either down a vertical shaft or a horizontal opening called and "adit".
Cribs
Cribs are the heavy wood supports that protect the drift. Cribs are installed to support the drift allowing for safe passage and use.
Logging Requirements
1. How many stopes are there in the Broken Boot Gold Mine?
2. What is the temperature inside the mine according to the thermometer near the largest Stope?
3. How long is the mine?
4. Name two minerals besides gold that are present in the mine.
5. How did the mine get it's name?
Pictures are not required, but they are appreciated. Please post a picture of you, your GPS or anything you found interesting anywhere around the mine.
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