It appears that the US Air Force is expanding their regional trunked radio system and will have Buckley Air Force Base moving off of the federally managed Front Range system.
The discussion of the recent changes can be found here:
http://forums.radioreference.com/colorado-radio-discussion-forum/317446-new-air-force-trunked-site-south-denver-metro.html
Indications from local listeners show that Buckley AFB will join Peterson AFB, Cheyenne Mountain and the Air Force Academy as part of a VHF/UHF, multi-state P-25 trunked radio system. You can see the system details here:
http://www.radioreference.com/apps/db/?sid=3593
For many years Buckley AFB was a subscriber to a UHF trunking system managed by the Federal Protective Service and shared with federal and military users. It appears that the military is consolidating their activity on their own radio system.
We will have to see what becomes of the UHF trunked sites that served Buckley to see if they are re-purposed for federal use or retired.