Well, days later after disappointment we dove deep into investigating this case and received an email a few days later from fellow marker hunter "Air Force Dave S," who had shot down my hunch of the marker having been relocated to the privately-owned Sutro Tunnel. At the time, we learned that the Storey County Historical Society arranges a tour just once a year during the month of June. We thought that if the marker was removed from US 50 we had hopes that officials might have moved it up here in a haste. Dave replied to the owner of the Sutro Tunnel Co. and the owner solidly stated that the marker was not at the Sutro Property and continued with some valuable information. In Dave's email interview, the owner stated:

"... Several years ago, the Boy Scout Troop in Dayton restored the marker and the sign at that same turnout.
The Troop took it down the same time NDOT started working on that section of 50 and nothing has been seen since."

Most importantly in a final statement, the owner barked:

"We don't want anyone to know where Sutro is. I'm glad because that landmarker really doesn't matter if people can't see the tunnel."

Unfortunately, some people fail to understand that history belongs to everybody. Even though an historic site may reside on private property, an historic marker (and all of its content) solidly belongs to the public. Thanks to the loss of Marker 85 the many thousands of people who whizzed on by US 50 would never know the fascinating chapter of Adolph Sutro and his Tunnel.

Update 2015

Curiously, the replacement of Marker 85 also came at the whim of a change in ownership for the Sutro Tunnel! As you read above, the former owner wasn't at all willing to share in the history of the tunnel. In contrast, the new owners have solidly marketed the Tunnel as a tourist site: even reaching out to three counties in efforts of inviting the public. Today, you can visit the Sutro Tunnel by booking a group or private tour. However, if I'm being completely honest here, the opening of the tunnel has invited a bit of a price punch to the gut (as evident by the Google reviews here). This has made Sutro, quite possibly, the most expensive ghost town you can visit in the world ... clearly benefitting from the fact that the tunnel is finally open to the public after three decades.

To see Sutro, you can book a ticket for $50, or pay $100 for a private one-on-one tour in the link below. This will pay for a 2.5-hour tour of the grounds, unlimited photo opportunities, and a small walk to about 200 feet into the tunnel itself. Regardless of the price, I think we can all celebrate that the tunnel is finally open to the public.