A good Callibeatis imitation; seems like every time I try to fish Hebgen or any of the Blackfeet lakes when these bugs are around I'm fighting wind with green water coming over the bow. Not a lot of materials and pretty simple and quick to tie. Tied this one unweighted; lead-free wraps in the thorax or a beadhead if you're looking for something a bit heavier.
hook - Mustad 9671 #12
thread - Uni 8/0 camel
tail/shellback - pheasant tail fibers
abdomen - ostrich herl (actually came from a feather duster)
rib - copper wire x-small
thorax -ostrich herl
wingcase/legs -pheasant tail fibers
Part 1
mash barb and attach thread and wire at 60% mark; keep tag end of wire on far side of hook bend
wrap wire back to point above hook barb
tie in a few ostrich herls and return thread to 60% position (normally I'd tie in the tail first but twisting the ostrich generates a bit of torque and I've had trouble keeping the tail in line; doing it afterwards alleviates any twisting and doesn't take any longer)
twist herl together
and wrap forward
measure some pheasant tail fibers (extend abdomen length behind the butt)
and tie in ahead of abdomen
trim pheasant butts, hold fibers against the body and start wire rib forward
continue rib through abdomen, tie off and helicopter the end
measure another clump (8-10) of pheasant tail fibers (abdomen distance) and tie in 1 hook eye width back from eye; from this point, the tying steps are pretty much like the Turkey Tail nymph