Eh, anything interesting is going to be inside and out of sight. The desert is so big that people aren’t going to be sneaking up on it without you noticing.

We’re not going to rely on obscurity to keep our research sites secure. People who have worked at similar secure sites report parking at the meeting building, changing into their work coveralls, going through a security screening and then being driven for an hour or two in a bus with blacked out windows to work in a sealed building with no windows before being driven back in similar conditions.

Using your existing classified development facility has the advantage that you can keep activities at it at a roughly constant level, so anyone watching from a satellite can’t tell if there’s more or less activity that would indicate something interesting. Just make sure that a dozen busses show up every day, regardless of how many people are in them.

It’s similar to how you can tell the Pentagons level of alert by looking at pizza delivery wait times at off hours on Google maps.