D-21 drones I have photographed (often with the SR-71 Blackbird examples) at March AFB, Castle AFB, Pima, Museum of Flight, McMinnville and the NMoUSAF.
D-21B #524
NMoUSAF 2018
D-21B #537
March AFB 2018
D-21B #533
Pima 2017
(need to pull drone pics from Blackbird shots)
D-21 #510
Displayed aboard M-21 60-6940 mother ship; Museum of Flight 2008
(need to pull drone pics from Blackbird shots)
D-21 #534
Evergreen Aviation Museum 2015
(need to pull drone pics from Blackbird shots)