Fished the Big Thompson below the dam. Nothing was hitting early but turned on once the clouds rolled in. Caught several fish dry flying with a size 18-22 BWO pattern. Then clouds went away and the fish stayed low. Continued to catch a couple more with a RS-2 trailed by a black midge (18-20). Biggest fish was around 16 and smallest about 12. Fish could be seen in all the predictable pools but very weary while the sun was out. Very light, subtle hits. Didn't see any spawning action as the egg patterns had no takes.