These are all targets for aerial bombing practice. You will find the old runways etc. from the AAF days just to the SE. You can also see that one of the runways is still in use. What you see to the NE is not an old runway but what is known as a tactical range with what are more real world types of targets like dummy aircraft etc. Notice the star like pattern to the NNE, that is a mock SAM site. Tactical targets are more real world targets while the the concentric circles where hits are scored just like typical rifle range shooting.
I was stationed here many years ago, around 1969.