Quote Originally Posted by flybugpa View Post
it may work ,here is a quote trom Pitt" never thought of September as a Mayfly month. When the PMDs fade out in August it tends to become hopper/beatle/ant time for me. Or Renegade time on tributary creeks. Or Damsel fly time on high altitude lagoons. We do get some diminutive Pseudoklingons on the Mo in September. But it's usually dinks that pay attention to those #64 fly specs. Somehow the Mahogony dun never became part of my repertoire. I don't think I've ever seen one before. But I've never gone to the Henry's Fork in the late season either. That is a handsome fly." it my work, i would resort to plan B s a back up
First - here is a response from another Montana angler, quoting from the same thread -

Sandy -

We do have mahogany duns in the fall over here in this part of the state. I don't pay much attention to that hatch simply because there are other things going on at the same time - hoppers, as you indicated, and probably some October Caddis.

But I did fish the mahogany hatch on the Bitterroot a couple years ago, in late Sept into early Oct as I recall, and caught some pretty nice fishies with a loop wing emerger similar to the one Byron posted. From a quick look at my photo album, I would guess a couple of the pix were from Rock Creek, but I am not positive that is where those pix were taken.

This is not a typical mayfly hatch, from what I have read, whether it occurs in spring or fall. The duns don't stay on the surface long, and some, if not all, do actually fully emerge subsurface. When I was preparing to fish the hatch, I went with an emerger / cripple style fly rather than a dun since that is the form the fishies are most accustomed to seeing - and eating.

John"

Second - Byron is planning for the Henry's Fork. The mahogany dun is a well known and regarded hatch on that river and when it is on, there is no need for a plan B. That is not to say that there will not be some other interesting things going on there in September.

John