Managed to catch a fair bit of traffic on 2319 (no patch), and it appear that it's CDOT 4R - Park County. Park County used to be split between several maintenance sections, but the 2013 map has it all in section 4.
So I've submitted 2319 as CDOT 4R
That sounds right, I also have 2319 as 4 Robert. Thanks for the help!
Also, we are definitely "missing" 2 Paul TAC, I heard trucks discussing switching to it a few weeks ago on 2-Paul (2502), but I couldn't tell which TG they switched to. It's possible I can't hear that TG from the big Denver-Metro sites, although I'm guessing I did hear it on a "re-purposed" TG and just didn't know for sure what I was hearing...