What is the Yuma Proving Ground you ask?? A huge area north of Yuma was set aside during WWII to test weapons and since then they continue to test not only weapons but everything connected with warfare at the proving grounds....for desert conditions. There are 2 other places used to test under jungle conditions and sub freezing conditions.
It was very interesting to see some of this stuff up close and to imagine what the conditions must be like. They also had a room in the museum dedicated to the holocaust, a stark and tearfully emotional reminder of why we need to be prepared. Let freedom ring.