Green Have~SwittersB
Green Haven~SwittersB

A prolific little fly fishing staple that likes those weedy, riffly runs that are pleasant to fish and behold. The nymphs are generally smaller (from 16 down to those pesky 20’s). Slender swimmers that can get carried into the currents in a late morning drift provide the opportune time to dredge with a nymph set up (whether you like a two nymph combo or a single nymph) work the riffles. 

 

 

Baetidae (Moja Mala Entomološka Zbirka~Sebastian M.)
Baetidae (Moja Mala Entomološka Zbirka~Sebastian H.)

 

 

 

Baetis Nymphs~Thym (Fly Tying Forum)
Baetis Nymphs~Thym (Fly Tying Forum)

Research you local streams for hatch info and local pattern favorites. The above patterns are obviously beautiful to any tyer. Also, a simpler Pheasant Tail Nymph would work. Smaller, slender (swimmer, not chunky) and medium to dark in color.      

Pheasant Tail Nymphs by SwittersB

 Fly Tying Instructions for PTN at Oregon Fly Fishing Blog . Planet Trout made a great suggesting, reminding me of the dark wingcase of the nymph…he uses black Krystal Flash for the wingcase and the legs..(see comments).