>>You are thinking of the old Titan I sites.
Probably. I just recalled reading about missile silos in Placer and Yuba long, long ago. I’m being a bit hyperbolic here anyway.
For Example: https://insurancenewsnet.com/oarticle/Mystery-runs-deep-at-old-missile-complex-in-Placer-%5BThe-Sacramento-Bee-Calif%5D-a-303577#.WiTASLaB3RY