Here's another good online resource for declassified information about the MiG's at Tonopah and Groom Lake:
The Area 51 File: Secret Aircraft and Soviet MiGs
The famous 'Det. 3 Security Manual' for the 'cammo dudes' is here.
Retired Colonel Mike Tarlton's LinkedIn listing gives an idea of how large recent operations are at Groom Lake:
Commander, Operations Group
United States Air Force
June 2010 – June 2012 (2 years 1 month)
Led 600+ military/contractor/government team comprised of 11 diverse squadrons conducting developmental and operational testing at a national test facility. Directed operations and maintenance for 25 aircraft types, and execute an $84M annual budget utilizing $4B in national assets.
https://www.linkedin.com/in/mike-tarlton-227a1998