The Blackbird Airpark is the world's only display of an SR-71A, A-12, and D-21 drone.  These three aircraft are all on loan and were restored and displayed by volunteers. 
 

Here is the A-12.  The yellow thing is the engine starter.  This aircraft was the first Blackbird built and first flew on April 26, 1964.  It was used for flight tests and never saw operational duty.
 
 
 

This is an example of one of the Pratt & Whitney J-58 engines that drove the Blackbirds past Mach 3.  Everything about the SR-71/A-12s is unique.  The engines can operate as either turbojets or ramjets.  The JP-7 fuel is used as airframe coolant, hydraulic fluid in the engine, and as fuel. 
 
 

The SR-71 is on the left and the A-12 is on the right.  The 3-acre airpark was well-attended that day.