[null and void]

I am pretty certain that there is more than one back up facility and they probably get lots of training and testing.

In a rational world I'd be certain of that.

[arderkrag]

In a rational world I'd be certain of that.

Thanks for ruining any hope I had!

[jagusafr]

There is. Been there.

Colonel, USAFR

[Lonesome in Massachussets]

I didn’t have a chance to research it, but I sort of remember reading that there are two back up sites. Just a guess, but they probably have significant remoting capabilities, just in case of the big one. Did find this:

Ground Stations
The GPS control segment consists of several ground stations located around the world.

•A master control station at Schriever Air Force Base in Colorado

•Six unstaffed monitoring stations: Hawaii and Kwajalein in the Pacific Ocean; Diego Garcia in the Indian Ocean; Ascension Island in the Atlantic Ocean; Cape Canaveral, Florida and Colorado Springs, Colorado

•Four large ground-antenna stations that send commands and data up to the satellites and collect telemetry back from them.
The monitor stations track the navigation signals and send their data back to the master control station. There, the controllers determine any adjustments or updates to the navigation signals needed to maintain precise navigation and update the satellites via the ground antennas. To further improve system accuracy, in 2005, the master control station added data from six monitor stations operated by the National Geospatial-Intelligence Agency to the six GPS monitor stations.

http://www.aero.org/education/primers/gps/elements.html