Military adversaries have plenty of sources of their own imagery, and the commercial imagery industry is large and international. It's just not a tractable problem to try to keep people from obtaining good aerial imagery of military installations, and it's become fairly rare for anyone to try. We know that various military organizations have taken active measures to prevent imaging of sensitive activity (e.g. returning vehicles to same parking positions before passes of known IMINT satellites) but it's not a very easy thing to do, especially in the US which is heavily covered by both commercial and foreign satellites in various orbits like sun-synchronous and Molniya.1
Some military installations do receive a degree of protection by means of restricted airspace which mostly prevents commercial aerial imaging, meaning that only lower spatial resolution satellite images are available. But even this isn't really that common, and there's no systematic restriction on commercial imagery operators overflying military installations if airspace permits it.
I put forth the question because I know that in some places (i.e. Northern Ireland), police stations and army barracks are obfuscated on Google Maps to prevent terror groups from using it to easily gather information for mortar attacks.
I suppose the chances of that happening in a remote part of the United States is much smaller but that with the resources the U.S Department of Defence have, I would have thought that they would take every precaution.
Edit: It appears it's no longer done in Northern Ireland.
Some military installations do receive a degree of protection by means of restricted airspace which mostly prevents commercial aerial imaging, meaning that only lower spatial resolution satellite images are available. But even this isn't really that common, and there's no systematic restriction on commercial imagery operators overflying military installations if airspace permits it.