I am planning on exploring some of the Columbia gorge rivers for trout when they open and I was wondering if there were any websites that show the hatches on these rivers. I would like to be a little prepared.
It is early for trout but in March weighted #4 to #6 Golden Stone Fly nymphs should produce and it's worth trying a Stimulator dry in a #6 or #8.
You may find that if it is a warm day that #16, #18 and even a #20 Baetis nymphs may work.
Rather than specific nymph imitations I would recommend soft hackles or Hare's Ears.
If I tried dries I would lean towards Parachute Baetis style for dry flies during a hatch.
These tend to come and go quickly.
I would use Stone Fly nymph and dries imitations if I had to choose only two flies.