Photo taken by Russ Nelson
License: Creative Commons Attribution-Share-Alike (CC BY-SA)
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BH Photo #313932
I've actuly snuck in there one time before they really bolted it shut, the beginning of the tunnel looked it was being used as a storage area for water equipment like boeis and such, I also recall it being very flooded to the point where you could only walk on the tracks, there was also some scraped equipment laying around further down the tunnel.