The Green Para Drake works great on the Eastern streams during the Green Drake hatch. I have numerous customers say it works well on the western trout streams as well. This is usually the last fly on the water as darkness approaches. Most mountain streams produce more of these than you would expect..just stay on the stream until dark.
Some of the finest fishing I've ever had has been in the Adirondacks on the green drake hatch.
This fly has an extended body providing a big mouthful for the trout.