We are building a network and this is one of the control points we came across. This was new to me. I was able to unscrew the glass and mount my antenna right to the plate on top. It was pointing in the direction of a Height MOD point up the highway about two miles. Thought I would share. Notice it has a squatter in the site backdrop. 
What the heck is that?
NGS Control Point. Seriously though, that was my initial thought also.
I get that, but what is that triangle shaped thing for and what is nesting in it?
PS. I like the way you can see the Apple logo of your phone in the glass.
That is a back drop for the sight so they don't shoot something past it I guess. The glass was old school HP and said it was property of NASA. Wonder if they want it back...
The metal structure looks like a corner reflector for being a radio frequency/microwave/radar target. Same idea as the glass, but for longer wavelengths.
Bill, it had a metal mesh kind of texture. I think you may be right. I have close ups if you want to see it.
That design was first used, I think, for the Darien Province of Panama mapping by Side-Looking Airborne Radar (SLAR) done by Goodyear Aerospace Corporation back in the 1960's.
I've looked at that thing for decades, every time I drive south on I-5. I always figured it was a control point of some sort, but never had the opportunity to investigate. Thanks for posting!
You bet. Thanks for all the feedback. I knew someone out there knew some history.
Reminds me of the time in the mid 60s when one of our brighter lights decided to put a traverse station on front of a plate glass window in a door that was about 100' behind the target.
@#$%^&*()_*&^%#$%^& were some of the words used when we could not get a constant reading as the door kept opening and shutting !
Cheers,
Derek
Very cool.
Thanks Derek, That was a good laugh. 🙂
That's something I could see myself doing. It does keep life interesting.