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“Bite-Size Bits of Local, National, and Global History”

South Pass City in Fremont County, Wyoming — The American West (Mountains)
 

How a Stamp Mill Works

 
 
How a Stamp Mill Works Marker image. Click for full size.
By Connor Olson, June 3, 2019
1. How a Stamp Mill Works Marker
Inscription.  As early as 300 BC, the Greeks use the primary components of a stamp mill - drive wheel, cams, and stamps - for pounding and hauling grain. The concept was adapted to crushing ore and became widely used in America as a gold recovery process.

Typically, mills were powered by steam engines. As the driveshaft turned, the cams rotated, lifting and then dropping the stamps at a rate of 90 times per minute onto the gold ore below. Each stamp weighed about 800 pounds.

Water was added to the battery box in which ore was being crushed. The splashing action created by the falling stamps threw bits of sand and gold against a screen along the front of the box. Larger bits bounced back into the box to be re-crushed, while the smaller particles passed through the screen and were washed down copper tables coated with mercury. The mercury would “capture” and hold the gold, while the lighter sand passed over the dense mercury film to be discarded as waste.
 
Topics. This historical marker is listed in this topic list: Industry & Commerce.
 
Location. 42° 28.307′ N, 108° 

How a Stamp Mill Works Marker image. Click for full size.
By Connor Olson, June 3, 2019
2. How a Stamp Mill Works Marker
J.J. Marrin Stamp Mill
48.72′ W. Marker is in South Pass City, Wyoming, in Fremont County. Located on the Flood & Hindle Trail. Touch for map. Marker is at or near this postal address: 125 South Pass Main Street, Lander WY 82520, United States of America. Touch for directions.
 
Other nearby markers. At least 8 other markers are within 5 miles of this marker, measured as the crow flies. Crushing Gold Ore (approx. 0.3 miles away); First Masonic Lodge in Wyoming (approx. half a mile away); South Pass City (approx. 0.6 miles away); Esther Hobart Morris (approx. ¾ mile away); South Pass City: Wyoming’s Biggest Gold Boom and Bust (approx. 0.8 miles away); The Carissa Mine: Cycle of Boom and Bust (approx. 0.8 miles away); South Pass and South Pass City (approx. 1½ miles away); Atlantic City: Surviving the Bust (approx. 4½ miles away). Touch for a list and map of all markers in South Pass City.
 
 
Credits. This page was last revised on August 10, 2020. It was originally submitted on August 2, 2020, by Connor Olson of Lemmon, South Dakota. This page has been viewed 52 times since then and 2 times this year. Photos:   1, 2. submitted on August 2, 2020, by Connor Olson of Lemmon, South Dakota. • Andrew Ruppenstein was the editor who published this page.
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Feb. 25, 2021