rfields5421 From United States of America, joined Jul 2007, 7681 posts, RR: 33
Reply 2, posted (2 years 6 months 3 weeks 1 day 20 hours ago) and read 5110 times:
Google Earth shows the other vehicles in a Nov 18, 2006 image, and the X-15 mockup added between July 16, 2011 and Dec 3, 2011.
It is also located at the north entrance to the NASA Dryden Flight Research Center.
Since that is an area behind locked gates not accessible to normal visitors or regular Edwards military personnel, I wonder if they were in the process of developing a display area before Dryden ended their public tours late in 2011.