They were swarming Saturday on the Indian Pass trail, near ADK Loj, but not biting too much (I received a few bites). Swarms seemed to be in "pockets" not constant throughout the trail, and things improved as the day went on (lunch near a stream was bug-free). We experienced no problems when walking, but most of the time we were stationary (doing trail work). Whatever you experience will depend upon location, weather, wind, etc. Be prepared with DEET, and personally I'd bring a headnet, and perhaps a bug shirt/jacket if you're camping, though I ended up using none of these.