So i'm digging my late evening excursions this June/July.
Get to the creek at 6:30 or 7:00, get in the water by 7:15, landing a few or two nymphing (in yesterday's case a fat fat fat 16 incher that pulled like a beast), float on down to some glassy water and fish dries till dark, catching lots of little fish and an occasional 12-13 inch scrapper.
Only downside is pulling out of the creek at night and nearly getting killed 6 times on the way back to the car.
Size 16-20 Mayflies at dusk, and size 12-14 caddis at dark are the trick.