Fun fact: The A12 flew from 1964 to 1967. The SR-71 flew from 1964 to 1999, ostensibly to fly over the Soviet Union. But the S-200 was deployed in 1966 and your average 130k ceiling Mach 6 surface-to-air missile gives no fucks about your 85k ceiling, Mach 3 spyplane.

It's entirely possible the CIA gave up on overflights because they no longer had access to the airspace. Silly projects like the Tagboard and whatever-this-is give credence to the notion that for the CIA, lookdown mattered a whole lot more than look-over-the-border-over-there-until-the-MiG-31s-achieve-missile-lock.

But to the Air Force? It's all gravy so long as it burns jet fuel.