2017 Mining History Association Tour

 

Tour of the U.S. Army Corps of Engineers'
Cold Regions Research and Engineering Laboratory
(CRREL) Permafrost Tunnel
Tour Hosts: Yuri Shur and Mischa Kanevskiy
June 18, 2017

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(Above, center) Before the MHAers go underground, Yuri Shur, one of our guides, explains the development and use of the Cold Regions Research & Engineering Laboratory (CRREL) Tunnel.  He is holding a steam point used by dredge miners to thaw gold placers in permafrost.

Hard hats and warm jackets are standard equipment underground where the atmosphere is kept below freezing to prevent thawing of the permafrost.


A map of the CRREL Tunnel shows the horizontal Main Adit driven by the U. S. Army Corps of Engineers and the Winze driven by the U. S. Bureau of Mines which slopes down to bedrock. Both openings were constructed in the 1960s.

The Main Adit is approximately 360 feet long.  It penetrates a frozen silt layer along the eastern edge of Goldstream Valley in the escarpment that was created by placer mining.

 

The Winze is approximately 148 feet long and has a 14% grade. It passes through the frozen Fox Gravel and bottoms out in weathered schist bedrock where the Gravel Room was excavated.

A close-up view of the Gravel Room on bedrock.

 

This diagram shows how the early miners used shafts in the permafrost to reach the gold bearing gravels resting on the bedrock. The gravels were hoisted to the surface during the winter months and processed in Long-Tom sluices when water was available in the summer months.

Photos courtesy of Mike and Pat Kaas

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