Not a standard USAF vehicle

[Matej]

Searching for some stuff I found this photo - it shows the big drilling machine in USAF markings, apparently used for building some underground support facilities. Not an usual USAF vehicle, isn't it?

http://www.skyshipsovercashiers.com/secretfacilities.htm

 

[Mr London 24/7]

Or is it?

The picture was from a dig at Little Skull Mountain, NV.

 

[GeorgeA]

Perhaps for an MX MPS tunnel?

 

[Michel Van]

that tunnel drilling machine was used for MX deployment to test
the Buried-Trench Mobility concept
more on this here http://www.secretprojects.co.uk/forum/index.php/topic,1063.0.html