While the DEA continues to utilize the UHF federal spectrum for it's primary communications, there have been some VHF federal channels that are utilizing the same P25 NAC of N156 that their UHF channels use. These frequencies have been noted in multiple areas of the country, but mostly in North Central Texas. The guess at the time is these are used for interoperability with other federal agencies, or perhaps a local task force. Confirmation is difficult, as all the communications have been encrypted. And so far, the only evidence that this activity is DEA related is the N156 NAC.
Previous reports have the following frequencies in use, all using the P25 NAC of N156:
173.6000, N156
173.7250, N156
173.8625, N156
In addition, I have heard 173.6750 & 173.7000 MHz used with the same NAC.
Here is a link to the current DEA frequency list:
http://mt-fedfiles.blogspot.com/p/dea-frequency-updates.html