....................... ......Fly Fishing Yellowstone National Park
Fly Fishing Yellowstone - Pale Morning Dun
One good thing about the early season hatches of the PMDs is that it is not uncommon for the duns to float a long time on the surface before flying away. This isn't true later on towards the last of the PMD hatches. They tend to leave the water fairly quickly. We consider a long time to be a minute or two versus a few seconds. Also, the early season hatches have a high percentage of cripples or duns that are deformed in some way.
Presentation: A down-stream or down and cross-stream presentation will usually spook less fish although you can fish pockets of calm water in pocket water using an upstream presentation. We fish our "Perfect Fly" Pale Morning Dun upstream or slightly up and across anytime we can do so without spooking fish. This is always the best way in streams with fast moving pocket water.
In slower moving, slick or smooth water, you may need to fish down and across. Keep in mind that even in streams with fast moving pocket water, the PMDs will hatch in the calmer, smoother water such as pockets and the outside edges of fast currents. If there are not a lot of fish rising to the emerging duns, then you may need to fish to an individual fish. This is a matter of getting your fly to drift over the fish at the right time. In smooth, slick water, this is not exactly easy to do without spooking the fish.
The hatches generally take place earlier during the hottest days of the season. You may need to be on the stream fishing by 9:00 o'clock in the morning which many anglers consider early, especially if they fished late the day before. The hatch may be over by 10:30 to 11:00 am.