Insects and other foods the trout may be eating:
1.   Blue-winged Olives - mostly Little BWO - Isolated hatches
2.   Cinnamon Caddis - Mostly Abrams Creek
3    Light Cahills - hatching
4.   Midges - hatching in isolated locations
5.   Little Short-horned Sedges - should hatch randomly for 2-3 months
6.   Streamers - matching sculpin, baitfish and small crawfish
7.   Little Yellow Stoneflies - hatching
8.   Green Sedges - hatching
9.   Little Sister Caddisflies - Mostly Abrams Creek
10. Eastern Pale Evening Duns - (called Sulfurs by some)
11. Sulphurs - hatching in isolated areas
12. Golden Stonefly - hatching
13. Little Green Stonefly - hatching
14. Slate Drakes - hatching
15. Beetles
16. Grasshoppers

The Learning Process - Part 13
I wrote about our first trip to Yellowstone National Park that took place ten or eleven
years ago at the first of this series and described a situation that occurred on the
Firehole River that we never solved. We found trout lined up each afternoon eating
something on a consistent basis but we were only able to catch a couple of them. I
am now quite sure they were caddisfly pupae but after three days of trying, we were
unable to match them or catch the trout feeding on them right before our eyes.

During the first couple of weeks of that trip we usually fished the Madison River
outside of the park at least for a couple of hours almost every day. We did fairly well
catching some nice brown and rainbow trout. We would usually fish nymphs in the
mornings and dry caddisfly imitations in the late afternoons. According to our video
shot logs and written fishing logs, most of the time we used a Hares Ear Nymph
below a strike indicator.

One day were fishing the wade only area and noticed a guy out in the center of the
Madison who seemed to have either a Rocky Mountain Whitefish or a trout on his
line the entire time. We watched him catch a lot of trout while we fished closer in to
the banks catching one every once in a while. After two or three hours, he waded
back to the bank where I complimented him on the fish he had caught. Using the
same strategy that most of us use, I managed to get him to show me the fly he was
using. It was his last day to fish. It was what I later determined to be a Green Sedge
Larva known as a Rock Worm.

At that time I didn't know aquatic insects well enough to know what the fly imitated.
He didn't call it by that name. He just showed the fly to me. At Bud and Lillys Fly
Shop that next morning Dick Greene helped me find the fly I described to him.
Armed with the killer fly, we headed back to the forty-mile riffle to repeat the
gentleman's performance from the day before. They were running a lot of water and
the current was flowing strong enough that it was difficult to stand up in knee deep
water but it was the same flows that occurred the day before. It was just tougher to
wade the slightly deeper water near the center of the river. We rigged the fly exactly
like the guy did using a big strike indicator. I fished the same exact water that he did
for at least two hours without catching the first trout or whitefish. It finally occurred to
me that I was doing exactly what I always cautioned anglers about not doing when
fishing for other species like bass and saltwater fish. I was trying to copy the other
guy's tactics that worked the day before.

The following day, we abandoned the Madison River and started out fishing the
Gibbon Meadows in the park. We were told that it was a little too late to be fishing
there but that at least we wouldn't be crowded. It was July 9th to be exact and the
water in the meadows was reaching the mid-sixties during the afternoons. The
Gibbon River meanders back and forth through the meadows with deep water and
undercut banks on one side and shallow bars on the other side. At the end of the
long pools the water speeds up some and then flows at a faster speed through a
narrower area. There are a few short riffles but not many.

When we started fishing at about 10:00 to 11:00 AM and noticed that trout were
rising near the end of a long pool where the speed of the water in the pool
increased a little and the current became obvious. There was several lines of
bubbles were the fish were consistently rising. What a break, I thought. I carefully
waded into the shallow side as Angie ran the camera. I was using a size 16
Parachute Adams, a fly that was a regular for me at that time. I proceeded to make
several excellent presentations where only my leader and/or tippet passed over the
trout. I put the fly over several rising trout but I had no takes. I was really getting
frustrated. My fly would pass right over the same point a trout's nose was coming up
out of the water on a regular basis without anything happening. They wouldn't touch
the fly yet they continued to eat something in the same spots over and over. I tried
timing my cast to the rises but that didn't work either. One time a trout rose so close
to my fly that it moved it sideways but the trout was after something else other than
my fly.

Angie called me to the bank excited that she had caught some little mayflies that
were hatching. I found out later they were Pale Morning Duns. I had read about
them but never seen one before. My Parachute Adams seemed to be about the
same size of the little mayflies but I thought the size 16 may be slightly larger, so I
tied on a size 18 Parachute Adams. I waded back out to the same spot where the
trout continued to rise. The same exact thing happened. The trout wouldn't touch
the smaller fly either. After about two hours had passed the trout began to rise less
and less. I finally gave up and went downstream to fish the riffle about fifty yards

The water is not really fast in the riffles, but it was much faster than where I had
been fishing. There were no trout rising but in a few minutes I had managed to
catch three small trout that averaged about ten inches long. So, I had what we call a
pattern in bass fishing terminology, so I moved on down the Gibbon fishing only the
short riffles. I managed to catch a few more trout but again, none of them were over
eleven inches long. I couldn't even catch a twelve inch trout.

The following day I knew what the mayflies were. We carried some them to the room
and video taped them. Using my books I quickly determined they were Pale Morning
Duns. For you that are not familiar with them, I'll just call them a Western version of
our Eastern Sulphur. That morning I purchased some of Craig Mathew's PMD
Sparkle Duns at Blue Ribbon Fly Shop and we returned to the Gibbon Meadows.
Wading out to about the same spot, I found the trout rising the same as they were
the day before. This time they took my fly. To make the long story short, I caught
eight nice trout, all browns. The largest one was near fourteen inches and none of
them were under twelve inches. The hatch only last about two hours even though
we had ideal, cloudy sky conditions. When it stopped, I stopped catching trout.

The PMD hatch represents the majority of all hatches during the summer months in
Yellowstone Country and throughout the West for that matter. From that time on I
never fished a Parachute Adams during a PMD hatch. I want go through the other
times we fished this hatch, even that first year at Yellowstone, but I can say it was
very often and we always managed to catch some fish. We found that hatch in the
Gallatin River later on, the Madison in and out of the park, the little Grayling Creek,
and many other places we fished during the month and a half long trip. For the last
two years, I have used my own flies for the PMD hatch. Our PMD Emerger with a
trailing shuck is a much better fly than the Sparkle Dun. Our PMD dun is better than
any fly you can purchase for the Pale Morning Dun. It works great during the hatch
even in extremely tough to fish spring creeks such as Silver Creek, Idaho.  We
didn't introduced it until last August but I used it one complete season in the
Western States including Yellowstone before we started selling the fly.

I encountered another similar situation that same year on the lower Henry's Fork.
We were fishing the tailwater near Ashton. The first time we fished there was in late
July. According to most anglers, the so called "good fishing" is over in that part of
the river by that time. When we first arrived at a good looking spot just below the
bridge, I saw trout rising regularly obviously eating something. As usual, I already
had a size 16 Parachute Adams tied on. I waded out in the stream a few feet below
the risers and began to cast in an upstream to them. I was fishing what I would best
describe as a wide riffle section and trout were rising everywhere. It didn't look like
any of the same situations we had encountered during the trip. I didn't think the
trout were rising to PMDs because the water was different from the other places we
had encountered them. We had heard and read about lots of other insects that
hatched at that time of the year and my guess was the trout were eating the Flavs
or Small Western Green Drakes that are supposed to hatch in the Henry's Fork at
that time of the year. It was difficult to tell what was hatching in the rougher water of
the riffles but whatever it was, obviously wasn't very similar to my Parachute Adams.
I fished about thirty minutes without a take knowing something was wrong. I decided
to make a quick trip to the one fly shop in town a short distance away.

Without bating an eye, the guy in the fly shop told me they were PMDs. As thanks, I
purchased some of his PMD flies and quickly returned to the river. On about my fifth
cast, I managed to hook and land a fourteen inch rainbow trout. In some situations
the PMD hatch will not last but a short time and such was the case that day. That
section of the Snake River is a fairly long distance from West Yellowstone Montana
and we didn't return again that year. I rediscovered one thing again on that trip.
You are not likely to catch trout rising to PMDs on a Parachute Adams, which at that
time was still my favorite fly. I was just beginning to realize the "fly" can make a big
difference, even in fast moving riffles with small calm pockets.

Copyright James Marsh 2009