I would echo the comments of Steve S. I've fished RF numerous times and he's right on. I was there this last weekend and scuds were the ticket (olive, anywhere from size 10 to 16). They were chowing on them. This time of year can be good, but just like any time of year over there, the fish can change their preferances at any time. I saw lots of mayflies on the water but surface activity was pretty slow so I was underneath as well. Lots of weeds that you have to maneuver around this time of year (streamside and in the water). Not uncommon for a big fish to take you into the weeds and leave you hanging! Steve S makes a great point - don't kill yourself casting to one fish. Make a great "first impression" and give it several tries. If they don't move for it, they won't take it. Try another fly or move on. Many times the same fly that was rejected will hook up in the next spot. Good luck!
Steve
Steve