I think there are several separate claims here that need to be verified before drawing that conclusion. Even if Bradbury Stamm Construction built the ranch and has worked on government facilities, that alone doesn't establish that the property was built to classified specifications or used for intelligence operations.
The connection to PROMIS is interesting historically, but the claim that Zorro Ranch was specifically positioned to continue an operation against Los Alamos and Sandia needs actual evidence. The timing and location might raise questions, but they don't prove coordination or surveillance.
I'd be interested to see reliable sources linking the ranch itself to classified work, rather than just connecting the companies, people, and locations. That's the part that would make this argument much stronger.