Originally placed by checkerbutt. Adopted by us in June 2003
after apparently being abandoned.
This cache has been moved from its original location. It is now
about south of its original spot at the base of a utility pole. It
is a tupperware container.
We are fond of benchmarks and the one at this cache site
appealed to us. It is part of a grid series of benchmarks placed in
the middle of a large cross shape and originally painted blue. Some
of the blue paint is still visible after nearly 40 years. It
apparently was part of an aerial photography project. After
attempting some research into the origins of these benchmarks, I
received the following e-mail from the Casa Grande Historical
Society on March 18, 2003.
*Local speculation states that these benchmarks were used for
aerial surveys by the army when they would fly their U2 planes. The
reason being was to synchronize their cameras for accuracy on
reconnaissance missions. We do not have information on the
benchmarks, but you might want to contact the army core of
engineers for more information.*
We believe this had to do with the Vietnam War since the
benchmarks were placed in the mid 1960's. If anybody has any
additional information, please post it in the log entries or send
us an e-mail. We are curious about its origins and purpose. FYI the
military no longer owns this land or uses it for any means. These
benchmarks are clearly abandoned, and most of the property
privately owned.For a bit of extra fun, check out the aerial photo
maps on the cache page. You can see the benchmark in the
photos.
Thanks to LegGoes and Dr. Angel for the following additional
information. *I checked the pictures of the benchmark and
definitely recognized it. I was an aerial observer for the Army
flying in the OV-1 Mohawks. We used these benchmarks for camera
alignment and resolution studies. There are others around the area
consisting of lines of different length and some with a bullseye
pattern but I don't remember all the locations. I have found a
couple of Army benchmarks and hope they post them like the NGS
does. I'm the brother of Oldhippy.*
New information courtesy of ClarionAce: It seems that these
benchmark crosses were used for the Corona Spy Satellite
Calibration project. .our first spy satellite. There are videos on
YouTube regarding it.
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