Ezra Zubrow provides the following background:
"Here is a quick version of the story of the photographs. . . I was a graduate student at the University of Arizona and during the summer of 1967 or 1968. I was working at the Southwestern Archaeological Expedition run by Paul S. Martin of the Field Museum of Chicago at the Hay Hollow Valley. I was a field foreman.
One day a group of B52's came over the nearby mesas very very low. This was the time of Vietnam. The sound was deafening and it seemed as if the earth shook and that they were only a few hundred feet above us. I remember looking up and I would swear that the bomb doors were open and that I saw a light inside. It was clear that they were doing some kind of low level practice and I thought it was a practice bombing run. When my ears stopped ringing, I thought to myself those planes must have cameras to record the dropping of the bombs and if they happen to come by again maybe I could ask them to take pictures of our excavations. So I wrote a letter to the "commanding general of the air force". I did not have a name or an address so I just sent it to the Commanding General US Air Force, Pentagon, Washington DC. I explained how useful photographs from the air were for doing archaeology in my letter and drove some 20 miles to Showlow Arizona to send the letter. When I did not hear anything I promptly forgot about it realizing that it was a "silly thing to have done." Two and half months went by and just before I left Vernon I received a package from the US Air Force from a colonel who was with a "reconnaissance" wing. In it was a letter saying that my letter had been received at the pentagon and had wended its way through various offices with a request that if it was possible to help us please do and here were a set of pictures of your excavations and the nearby area. To say the least I was thunderstruck. I had no idea how they had done the photographs but there were a set of 9x18 negatives and prints.
When I returned to Tucson for the fall semester a few days later, I started to look at the photographs. I realized that I wanted to say thank you and sent a letter saying thank you to the air force. It then occurred to me that it would be a nice thing to do to call and say thank you in person. I called the Pentagon and after several calls they provided me a number to call. It had the same area code as Tucson and I realized that the colonel was probably stationed at Davis Monthan Air Force Base. So I called the base and asked if I could make an appointment to meet him and personally say thank you. I got an appointment the following week and went out to the base. At the guard house I told them I had an appointment with the colonel and they told me to wait at the gate house which I did. After about 15 minutes a soldier came out with a car and asked me to leave my car at the gatehouse and he would drive me into the base. The car actually had blacked out side and rear windows.
We went into a low lying building and there were several people there including Colonel Y and a Lieutenant X. I told them how appreciative I was and that all the other archaeologists at the Southwestern Archaeological Expedition appreciated their help as well.
I had no idea with whom I was dealing. They showed me around various rooms and laboratories for photography and finally came to a room with a large chalkboard in it. On the chalkboard was a listing of missions, plane numbers, and pilots. There were a range of missions scheduled for several weeks and when I realized that several of them were over Vietnam, Cambodia, China, and Russia I stopped in my tracks. I looked at my hosts and said what kind of planes were they flying. I still thought it was something like a B52. They said it was the U2. I was speechless and as I later learned my mouth dropped so wide that all the men in the room started laughing. They said that if I wanted to watch one land it was going to land in a few minutes and as I was leaving I could watch. Of course I wanted to.
So as I left, I said thank you again and the Colonel and the Lieutenant said if they could help more, they would be willing to do so.
It turned out that Lieutenant X and I were about the same age and that we each had just been married a short time. We both were in a "foreign town," Tucson. So the two couples began t to meet for dinner and joined some other young couples who were in Tucson for the first time. The following semester, I had the idea of photographing the Pueblos. I asked Lieutenant X and Colonel Y if it might be possible and they said yes. I went back to the base and we sat with maps and plotted out the exact flight plan.
And that's more or less how it happened. The Colonel, the Lieutenant, and I continued to be friends for many years."
 Email from Ezra Zubrow to archivist Gina Rappaport, April 22, 2010.