Noted the 30th of August were two MIL visitors
169533/QB-533 KC-130J VMGR-352
160853/G-(453) T-44C VT-31
This General Aviation airport regularly sees military visitors, every week something military seems to be visiting, sometimes even daily. There are often Hornets, Hercules and training aircraft dropping by. Easy to watch traffic from the tower side near the jet center or have a look at the tarmac.
The majority of passing visitors in the area do land at Colorado Springs though. So for choosing an airport to watch MIL stuff, it is better to go try your luck there instead on Centennial or Buckley. I did visit nearby Buckley as well but no flying there on that Friday (Buckley does not see a lot of movements).