Buried thingy at Kryptos site?

So this effort to verify came from a Kryptos conversation following Ed Sheidt’s presentation to the ACA recently:

Klauss:  Was something placed by Kryptos that we need access to to solve Kryptos?
Jim:   Yes, there is something buried adjacent to Kryptos.   Jae and I went back to visit a couple of years ago, and they had removed it, but it is important.
Donna:   Well, since it is not there anymore, can you tell us what it was or do you want to wait for that?
Jim:   The thing that was buried is a bronze USGS marker. It was half buried. It had little cross hairs on the top of it.
Sooo, I sent an email to USGS:
Hi guys, Jim Sanborn was answering questions after an American Cryptogram Convention and mentioned a USGS marker.  He claims it was bronze with a crosshair at the top and was half-buried in the courtyard of the CIA’s headquarters.  The GPS coordinates in his sculpture were 38° 57′ 6.5″ N 77° 8′ 44″ W if that helps at all.  We’d like to confirm this and find out some more details on how it was buried there, why it was removed and where it is now if that’s okay.  Any information will be pretty informational as most of us don’t know much about USGS markers.  We run a humble blog that serves as a discussion board for this sculpture and anything you can tell us will be disproportionately appreciated to normal requests about USGS markers.  Thank you over and again!
And they responded:
 For geodetic information, contact the office that covers your area of interest. The Denver Science Information Services office (at the address shown below) has information on USGS geodetic control (bench marks and survey control) in the following areas:Alaska, Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Texas, Utah, Wyoming, California, Hawaii, Oregon, Washington, American Samoa, and the Trust Territories; is available from:Denver- Science Information Services
U.S. Geological Survey
Box 25286, Building 810
Denver Federal Center
Denver, CO 80225

Phone: 303-202-4200
Fax: 303-202-4188
E-mail: infoservicesatusgsdotgov

For all other U.S. areas, contact the Rolla Science Information Services

U.S. Geological Survey
1400 Independence Road, MS 231
Rolla, MO 65401-2602

Phone: 573-308-3500
Fax: 573-308-3615
E-mail: mcmcesicatusgsdotgov

Regards,

U.S. Geological Survey
Science Information Services
Office of Communications and Publishing
12201 Sunrise Valley Drive, MS 507
Reston, VA  20192
888-ASK-USGS (275-8747)
Cynthia Manuel
So I re-sent the email to Rolla.
And they responded:
Hello,

After some research we have determined the “Benchmark” disk actually belonged to the USC&GS. Now the agency is under NOAA and is known as NGS or the National Geodetic Survey. They have markers all over the DC area.  The word from them is the “marker is DESTROYED no other information can be found”.
The agency does have a nice online database if you want to check it out: http://www.ngs.noaa.gov/NGSDataExplorer/
USGS-Rolla, MO
Office of Communications and Publishing
Science Information Services
888-ASK-USGS (275-8747)
Follow @USGS on Twitter
Find USGS on Facebook
Follow @USGS on Instagram
Circle USGS on Google+
So at long last we know what it was and what it looks like.  I’ll try and get in touch with NGS at NOAA and update this post if they ever respond.  Now that we know what it was, what does that mean for Kryptos?