Ground-Mobile Command Center
The Ground-Mobile Command Center was, or is, a U.S. Army program to develop and deploy hardened and secure, mobile command posts for use by the President of the United States to command retaliation and counterattack by the U.S. armed forces in response to a catastrophic assault against North America. == Development and purpose == The Ground-Mobile Command Center program was initiated in 1981.
Source: Wikipedia — Ground-Mobile Command Center (CC BY-SA 4.0)