It sounds like you may have stumbled across a disused Minuteman complex. Do you have any idea what it was? There were silos for Atlas F, Titan I, Titan II, and all of the Minuteman series. At peak deployment, there were 1,000 Minuteman silos. It was often remarked within the Boeing Company that they made more money on the ground part of the system than on the missiles.

I will correct myself, now that I have looked at your map. Maybe a Titan II silo? These have silo launch doors; Minuteman has a sliding cover. But I don't see any indications of the Titan II exhaust ducts, so maybe a Titan I silo? Strategic defense was a serious matter in the 50s and 60s. Maybe from a more adult time.

It sounds like you may have stumbled across a disused Minuteman complex. Do you have any idea what it was? There were silos for Atlas F, Titan I, Titan II, and all of the Minuteman series. At peak deployment, there were 1,000 Minuteman silos. It was often remarked within the Boeing Company that they made more money on the ground part of the system than on the missiles.