[1] The range consisted of 272 concrete calibration markers embedded into the Earth's surface in and around Casa Grande, Arizona, United States.

[2] The markers are commonly (and erroneously) believed to have been used to aid camera calibration for the US Central Intelligence Agency's Corona spy satellite program;[3] in fact, they were used as references for aerial surveys through photogrammetry.

Following the launch of Corona satellites in the 1960s, the US National Foreign Intelligence Program determined that there was a need for calibration under the Controlled Range Network.

By the late-1970s, the US Army Map Service considered the targets to be obsolete for their use as the land on which they were situated had subsided because of groundwater extraction.

[3] The Casa Grande Calibration Targets pictured in the image gallery are two of the few remaining ones in the Sonoran Desert.