That would be over on Katmai, I've not fished it but would suspect that you should be able to use about anything for the trout. Of course egg patterns are always favored but I did well everywhere including on Alagnak which is in the area using Sculpin patterns last season. My style fishing is better suited to the Sculpins and assorted tubes and streamers than to drifting an egg so they are what I use. A guy fishing an egg may catch more but you can raise some really nice fish swinging streamers here.
That time of year egg and flesh patterns of all sizes will catch fish. Swinging sculpin or leech patterns (ESLs) work really well too. You will have to work hard to NOT catch fish. I would even bring some topwater stuff like mouse patterns to mix it up. When I know the fishing is as hot as it will be for you I like to try all sorts of stuff, almost seeing what they won't hit just for fun.
I can't remember which flies we found working well, but I can share with you a trip there.
in the 80's when I was spending the summers teaching fly fishing at Katmai Lodge when Tony Sarp owned the place we took a trip over to the Moraine.
The float plane dropped us off at a little dinky pond about a mile or two from the river and we hiked in to the Moraine. The bush pilot said, "meet me back here about 4PM"
All right, it was a HOT day (yes they do get hot days in Alaska) and we were drenched with sweat by the time we got there.
The fishing was off, Yes, thousands of fish in the river but it was one of those days they wouldn't take. Not even the grayling would rise to a fly.
We decided to quit early and hiked back about 2pm and found the Cessna waiting for us. The pilot said, "I'm glad that you guys got back early, there's a front coming in. Now, I have to make two trips to get you out. The Cessna takes 7, but I know I brought you all in together, but I can't get off and clear the trees with all of you. So, I'm taking 4 out on the first trip to a larger lake and then coming back for the other three.
Now, if the front beats us, I can't get back, so here's some water, blankets and my shotgun in case of bears. (There were about 20 in sight on the tundra from our little higher point of view).
The front should blow over in a couple of days and I can get back in.
Well, he beat the front, I loaded the blankets an shucked out the shells in the pump. chunk, chunk, click, click, click, Oh O! You gave me a shotgun for bears with only two shells? Then I looked at the shells, #6!
"Er," the Bush Pilot responded, "I forgot I was bird hunting the other day and didnt' change the ammo!"
Good thing the bears kept their distance, two blasts of #6's would really have ticked them off.
(I now have a Ruger .375 Mag carbine of my own for those places)
I did this exact thing last August.
Was a lot of fun.
Between the fishing and the bears I don't know which was more fun.
I caught Rainbows, Grayling, Arctic Char, Sockeye Salmon and I even got a Lake Trout.
As far as flies, if your going with a guide I'd bet you'll be using Beads. Are you using a guide? Who? If your going with a guide check with him to see if he'll be supplying flies. Then you can bring some other stuff if you want just to mess around with. But Beads are the most effective fly in that place in that time. The fish are there to eat the salmon eggs. I did try swinging flies for a couple of hours and didn't have a tap. Switched back to the bead, bang, fish on.
Fishing was best early morning and evening. There were times that you'd catch a fish on every cast. Then you'd go 2-3 casts without a fish and wonder what the heck was going on?
I would suggest this, be prepared for cold wet weather. It was overcast, windy and rainy every day we were there. The sun only shined for a couple of hours on 2-3 days. Better to have too much than not enough.
The bears are interesting to watch. You can be fishing when a bear will be walking up the shore looking for a salmon. The bears will just keep on coming until you turn around, face them, wave your arms and yell "hey Bear, Go away Bear". Then the bears will stop, swing their heads side to side, turn around and walk away. Its up to you how close you will let the bears get. Having a guide was nice at times like this. You could concentrate on fishing. I went out in the evenings and early morning by myself almost everyday. I had to be careful and watch for bears. We never carried a gun. I'll bet we saw at least 2 dozen bears a day easily. Some we would stop fishing and watch for an hour at a time. Some are really good at catching salmon. They stalk them from the bank like a cat. Then all of a sudden they will leap into the water and pop up with a fish in either their paws or mouth. The closest I got to a bear was about 20 ft. A pair of cubs and the mother. Mother had walked by us but not as close. The cubs were always lingering behind. They decided to run up the shore instead of following mom down river. When they ran up river they came to within 20 ft of me. They found a dead salmon and they played with that for awhile before running after mom.
You will have a great time. I'm looking forward to going to Alaska again but to do the Silver salmon and Steelhead.
---------- Post added at 02:34 PM ---------- Previous post was at 02:22 PM ----------
Oh, and size wise, most of the rainbows ran in the 15-20inch range. but its not uncommon to catch one in the 20-25 inch range and occasionally you'll get one close to 30. Anything over 30 will be unusually large. They do fight like crazy. I was always surprised at how small alot of the fish were after fighting them for a couple of minutes.
Last time I Fished The Moraine it was also late August we Flew down from The Kvichak Lodge after shooting some Red Grouse Fishing for Salmon on one of The Lakes Fishing & Bear Watching at Brooks Falls even though there were some nice fish around I feel we were a little late as I agree with Ard I'd rather be a Little Earlier & swing Streamers than use Beads any Day..
Moraine Creek as well as Funnel Creek which runs into it is very popular that time of The year as not only people are Fishing The Bears are plentiful eating Salmon to Fatten up for The Winter as I remember it well I counted 23 Bears also one Half Grown Bear even came up & ate The Salmon he caught about 15 Feet From us.
There was 2 or 3 other Planes from other lodges there as well one which brought in a load of Photographers.