First, I have to admit that I have no idea what CCN means. That said, I think the market here is the same as elsewhere. Summer Associate class sizes are down all around, and Denver is no exception. I also believe that firms here are giving CU/DU grads more preference over out of state schools. It seems that big firms have been hesitant to hire grads out of DU in past, but seem to be warming up to the idea. This combined with smaller class sizes may be squeezing out those who have ties to Denver, but went to school elsewhere.
"CCN" means students from Chicago, Columbia and NYU, which tend to be banded together in the rankings.
As for Denver hiring, I think it breaks down to two things. First, the biglaw and midlaw legal markets here are disproportionately small for a metro area this size. Not quite sure why -- my suspicion is that Denver really blossomed from a run-of-the-mill midsized city to a regional capital of sorts in the last 20 years or so, and by then, travel and technology made it a lot easier for the big players from Chicago and California to do stuff out here remotely. But in any event, you really only have one true native biglaw firm (H&H), and they don't do a ton of entry-level hiring. Then you've got a handful of firms that are on the border between biglaw and midlaw (DGS, HRO, S&H) and big offices of out-of-town firms (Faegre, Snell, Dorsey), but even if they hired a proportionate number of summer associates (and they don't for the reasons given below), offices in the 50-150 range can only hire so many summers. Combine that with the fact that you have the tip top students at CU and DU (maybe the top 20-30 at the former, and top 10-20 at the latter) taking up maybe half the SA spots in a given year, and it's a tough nut to crack for out-of-towners.
The second thing going on is that Denver is a hugely popular city for laterals (I know; I was one several years ago). I think there is a big sense among some firms that it's silly to spend a ton of money on a SA program and even training new associates, when they are going to be applying in droves out of NY or SF or Chicago -- with (real) biglaw training -- two or three years down the road.