Got the idea from Bruce Staples' Flies For the Greater Yellowstone Area. Tied here as a callibaetis; adjust the wing angle to a horizontal plane and tie with either a traditional hackle collar (trimmed on the underside) or a hacklestacker to make a spinner (it might work as a grey drake, too)

hook - Mustad 94840 #14
thread - MFC 8/0 sand
tail - hackle fibers badger
body - dubbing hare's ear
wing - hen badger (winger parachute style)
hackle - badger (oversize by 1)

Regards,
Scott