How ironic that you should post a link to these. That 14th photograph, the one showing the silver miner with his pickaxe inside the mine, is the exact picture that was the inspiration for this photograph I posted for fun a couple of weeks ago as I was going through old negatives.
Of course, we had it a bit easier than Mr. O'Sullivan with Coleman gas lanterns, a Nikon F2 with Vivitar 292 electronic flash, and Tri-X. Both my field partner that day and I were well aware of Mr. O'Sullivan's legacy. We were also intimately aware of the history of the Gold Hill/Virginia City Comstock Lode mining district and era.
Interestingly, at the time my photo was made we had an opportunity to visit and tour the Savage Mine in Virginia City. It was still being worked at the same 900-foot level mentioned in the caption. This must have been above the water table level as defined by the Sutro Tunnel drainage, since I don't believe they were pumping any longer.
Unfortunately, our schedules didn't work out, so we missed that chance. I always regretted that, as the Savage Mine was the last of the original Virginia City mining operations still in business.
[Edit: If anyone is interested in reading a wonderful historical account of the Comstock Lode bonanza and those involved with it, take a look at the book Comstock Mining and Miners by Eliot Lord, first published in 1883. It's the best there is on the topic and reads a little bit like an antique Indiana Jones adventure. Great stuff.]