Yes, almost all of the road racing in the Front Range of the Rockies is sanctioned by ACA (but you can race on a USCF license and buy one days). Re the Dead Dog: some of the CAT3's love that distance and some of them hate it. The hard part is (according to racers - of which I am not one), is that the final 10 miles is usually into a head wind with 1100 ft of climbing. Pretty tough after the first 76 miles.
Unfortunately the ACA is in a bit of turmoil right now. I hope they get it all straightened out before the spring road season starts.