http://www.lazygranch.com/images/basecamp/basecamp_party_shack_july2009.jpg

This building looks like it is still under construction. It is a
prefab from Engineered Structure Inc out of Boise (ESI), though
nothing shows up on the government pages regarding bidding. It is
located near the house part of the base, so I guess it is a party
shack, mess hall, etc.