Debunking the Arizona Concrete Crosses …one myth at a time.

(Yes, this will take a while…)

If you haven’t noticed yet, this is really starting to bug me. The amount of web pages, videos, and general chatter about the “secret in plain sight” near Casa Grande blows my mind. Since the myths themselves have perpetuated via short sound-bites, flashy videos, and really shallow explanations, I’ve decided to compile the list of counter-references in similarly short explanations (with pictures! when available).

If you’re not tracking what these crosses are, here’s a quick (wholly disputed by me) synopsis:

Plotting of the remaining concrete crosses (Courtesy of Google Maps)

“The Corona Satellite Calibration Targets consist of 272 (273!) concrete calibration markers embedded into the Earth’s surface in and around Casa Grande, Arizona, United States. The markers are commonly believed to have been used to aid camera calibration for the Central Intelligence Agency’s CORONA spy satellite program. The markers formed a square 16-by-16-mile (26 by 26 km) grid, and were maintained from 1959 (1966!) to 1972. Some of the original markers can still be found on satellite maps and ground inspection.”

To be clear, the assertion I am disputing is:

“The Arizona Concrete Crosses were built to calibrate the CORONA spy satellite system, and were abandoned in 1972 at the end of the program.”

Within any scientific discipline, this is called a hypothesis. I would like to propose a null hypothesis in its place:

“The Arizona Concrete Crosses were not built to calibrate the CORONA spy satellite system.”

My alternative hypothesis is: “The Arizona Concrete Crosses were built as ground control points providing a known datum for aerial photogrammetric cameras. Any use of the crosses by CORONA was supplemental.”

If you’ve read this far, feel free to use the links below to familiarize yourself with the Concrete Crosses and the alternative facts used to describe their origins and use.

Myth Reference Links:

YouTube Videos:

You shouldn’t believe everything you see on YouTube or social media… or even this blog…without researching it further. Every assertion I make on these blog postings will have quotes from declassified references from the U.S. government’s files on CORONA and the National Reconnaissance Program. I will provide links to the NRO’s “FOIA for All” program which holds many CORN docs (not “corn dogs,” as my son misread).

While this approach may be overkill and present these posts like they are research papers, I will provide enough plausible information to make you think about the hasty generalizations made about these concrete crosses in Arizona. But, I will warn you… truly understanding the *real* story will take longer than those five-minute YouTube videos.


3 thoughts on “Debunking the Arizona Concrete Crosses …one myth at a time.

  1. Hi Joseph…I see your still at it with the ‘Corona” crosses. Glad to see it. I have swung over to your view because there just simply isn’t enough evidence to convince me that these were constructed solely for the CORONA project. I’m the guy who has been Ground Truthing every site visible (and many that aren’t) and I wanted to add one thing. You crossed out the 1959 date as a starting point for the grid. In various Internet articles I see dates vary for the start (or existence) of construction of the grid from 1959 to 1965 to 1966 thru 1972. The CG Dispatch article states that construction wasn’t going to begin until the fall of 1968. So that rules out anything prior to that unless we are talking about site surveys and acquisition of lease parcels. One of the items I have been cataloguing is the date stamped on the brass benchmark. Most of them are 1966, a sprinkling of 1967 and 1968. But that doesn’t mean that is when the markers were actually poured. The cement center cores were pre-fab and dropped in a hole…they would have been constructed before the teams actually got out to the site. Another oddity is that in about 75% of the cases I have observed, the 4th digit is stamped with a different size and configuration stamp leading me to believe the brass markers were manufactured and stamped 196 leaving the 4th digit to be added later as needed. I picture a whole surplus of these brass markers sitting in a warehouse waiting to be shipped and used where needed (not just for these aerial markers…i have seen virtually the same marker used in the desert on elevation markers not related to this grid). Just because a grid marker says 1966 does not necessarily mean it was constructed that year. If the grid was actually constructed in the winter of 1968-69 (The cooler part of the year so that makes total sense) then to me, that’s way late in the Corona game and camera technology (I would think) would have out-stripped the need for this grid.
    FYI: I excavated one complete core and as far as I know I am the sole possessor of the information obtained. They are 36″ long, 8″ diameter at the top and 10″ at the bottom so they are tapered which makes extraction a real chore, and weigh 205.5 pounds give or take. It has a seam running down it which clearly shows they were pre-constructed and not poured ‘on-site’. They are also reinforced with (3) 3/8″ diameter rebar.
    I hope your search turns up the origins of this grid because I am curious as hell. I think there is an office of the Army Corps of Engineers in LA and I would think that office would have jurisdiction, if you will, over Arizona. Maybe there’s something there since they were the ones who awarded the contract to the Phoenix construction firm? Another side note. I did some digging on that construction firm. They built Tempe Diablo Stadium (a major site for one of the Cactus League baseball teams spring training games) back in 1968 as well so they are no strangers to large projects.


    1. Hey Mark,
      Hope you’re doing well. I sent a few attachments over the last few days regarding Casa Grande. Let me know if you want to discuss further – those images of your “brand” were awesome! ~JTP


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