Rumor of road closures for national defense purposes

I live in Southern California near San Bernardino. Today on the way to work I caught wind of something curious at a gas station.
First on the way up the mountain I ran into an inordinate number of black jeeps. I must have passed 4 or 5 of them on highway 330, which isn't such a busy road. Whatever, call it a coincidence. It really probably IS but I'm paranoid so anything black in large numbers looks like a government fleet vehicle to me.

When I am in the gas station I overheard something strange though. The manager of the store was explaining some road closures to somebody- no mystery there I figured, I'm part of the construction crew that is shutting them down. Until I hear the manager say that the federal government had ordered the road in question shut down for "national defense" reasons.
I meant to butt in and ask what road they were talking about but by the time I had paid the manager had gone to the back of the store again and I had to get to work anyway.

Of course this all leaves me wondering what a tiny mountain highway on bigbear mountain has to do with national defense. The only thing I can imagine is that if you wanted to move troops from 29 Palms without putting them on the I-10 and showing them off, the way to do it would be to come up the mountains and bring them down to the 215/I-15 which runs past March ARB.

I'm going to gather more details obviously and post them ASAP. For the time being I am just impatient and wanted to see if anyone else knows of road closures or other strange transportation-related orders from the government being made for "national defense" reasons.