I wish I had a report for you, but I've been fishing down south to avoid the I-70 traffic. Once winter hits, and I'm up in the mountains for work more, I'll be fishing the Blue probably once a week, but for now, I'm avoiding it because of the crowds and also because the fishing has declined from the pressure.
Don't get me wrong, it's still a great fishery, but having to battle other fisherman for a spot or having someone cast over your shoulder gets pretty dang annoying. That's why I love fishing it in the winter when there's not a lot of people around and the fish aren't so lock jawed.
But the good new is, the fishing hasn't changed much all summer except for the heavy fishing pressure so the "standard" attack plan still works.
I've attached a map to help you get started. These are the most commonly fished stretches. I-70 hole, rodeo hole, cable hole, etc...
Red are the holes, green is where to park.
If I were you, I'd head up towards GM instead and fish the inlet. The Kokes are starting to run and the rainbows and browns will follow eating eggs. You'll have to avoid the snaggers, but fishing above and below them will yield you some fish. You might even hook into some kokes! (Think pink! A pink san juan will get the kokes bitting, and fish eggs for the bows and brownies.)
But if you are dead set on fishing in town, think small. Use a 6x leader and 6x fluro, 2 or even a 3 fly set up. size 18 is the biggest I would even think of using. And I would ALWAYS have a stalcup's mysis or craven's mysis in size 20 tied on. Also, use a beadhead lead fly, and fish with no weight. A tungsten hare's ear in size 20 is perfect. Round out your rig with a midge, or jujubaetis. If they are actually taking dries (actively breaking the surface, not slurping), a size 20 sprout's midge or bwo should work. If they are just slurping, they are taking emergers sub surface. A size 22 black rs2 fished in the film will fool those fish.
If you find that all the holes are taken, or the fish aren't biting around the outlet mall, fish the Blue behind Chipotle up to Cutthroat Anglers. Less fish, but these fish are also less pressured.
Good luck up there, and post a report when you get back.