Midges and blue-winged olives continue to dominate. Midges are always present, but look for blue-winged olives in the late morning and early afternoon. Size 18-20 patterns, such as Sparkle Duns, CDC Baetis, and Parachute Baetis, are needed. Blue-winged olive nymph imitations, such as Pheasant Tails, are a good subsurface option. Use a 6X tippet with all your blue-winged olive and midge patterns.
Scuds are also a good choice. The conventional wisdom is that scuds turn orange when they are pregnant and trout prefer them that way. Jeff Morgan, Westfly's fly-tying columnist, has researched this issue carefully and states that the conventional wisdom is wrong. The real story is that a parasite gets into scuds, and this shows up as an orange spot under the skin on their back. Fish biologists ran an experiment and determined that trout focus on scuds with that bit of orange, perhaps because it makes them easier to notice. So tie your scud patterns with a dab of orange dubbing on the back and see what happens.
In addition to the scuds, blue-winged olives, and midges, put dark brown Hares Ears, Brassies (or better, CDC Bubble Brassie), and leech patterns in your fly box.
Callibaetis can show up here in April. Carry size 14 gray Sparkle Duns, Callibaetis Cripples, or Parachute Adams. Underneath, Flashback Pheasant Tails and Hares Ears draw strikes. White Woolly Buggers or leech patterns are another option.
Mornings may be your best time to fish. As the day warms up, weeds lose their grip on the bottom and float to the surface, making good drifts more difficult to obtain.
Watch for rattlesnakes and take precautions against ticks. After a day of fishing, do a strip search for the latter. You can find them in anywhere, but be especially attentive to any folds of flesh or hairy places, and your back. Carry a tick removal kit and know how to use it.
For more on April tactics and flies, see the Rivers in General forecast