I fish the Upper Colorado River quite a bit and here's a few combos that are deadly out there.
Royal Wulff and a Chama Chicken
Another great set-up is this Adams hybrid that I tie with deerhair tail and peacock thorax with brown hackle in a size #12-14. Tip that with a #18 X-Caddis
You can't ever go wrong with a hopper either. Tip that with a Adams Hybrid (above) in a #16 or a small Wulff.