We've had boats on the water a few times in the past week and a few more guide days in the book before the end of the month. We call this early season the shoulder-season and the guides are always happy to get a few trips pre-runoff. We've been in the middle of localized melt/run-off for about a week now and although it initially slowed things down a bit, the fish seem to have settled back in to the higher flows and levels and are feeding.
Although your best success will likely be sub-surface you may get into fish feeding actively on midges.
Flies to try:
Streamers: black and white clousers, Bow River buggers, skiddish smolts, mini-dungeons, leech patterns.
Nymphs: San Juan Worms, stonefly nymphs like the rubber leg squirrel, small beadhead nymphs; princes, pheasant tails, red devils, red copper johns.
Dries: Griffith's gnat, klinkhammer.