Silvers in Alaska
After checking out the Hidden Cove web site, it seems to me as if you've picked a good place. I've fished Alaska for silvers (cohos) for the last 10 years, and it's become my favorite fly fishing adventure.
One thing I like about the situation you're in, is that you can walk to the fishing. Do not get yourself into a lodge that offers only fly-out, as you'll might be spending your time playing cards and watching it rain through a 10 foot ceiling. If you've booked some time in September, that's usually the best time. If the fish are in, the week will go very fast. Too fast.
As for flies, tackle, etc. go with what the lodge recommends, then throw in some red General Practioners, some fuchsia Muddlers (deer hair/rabbit strip), some chartreuse Muddlers, and a few Clousers in the bait fish shades. Sometimes the fish will want something really small, so have an assortment ranging in 6's up through 1/0's or larger.
Blue is often a good color for silvers, particularly when combined with white. One of our hottest flies last year was a size 4 bead head in blue and white -- it was the go-to fly when all else failed.
Throw in a few Crazy Charlies in sizes 6-4 in chartreuse, fuchsia, black and purple.
I've never fished Hidden Cove, or any where near it, but I've had good dry fly luck elsewhere with Pink Pollywogs retrieved slowly (although with a visible wake) in still or very slowly flowing water. The best dry fly fishing I've had is when the fish are showing constantly in calm water. My experience has been that, when casting into a school, a fish will rise immediately when conditions are right. The second cast may produce a swirl or two, and the third cast is, again in my experience, generally ignored. I like to hit and run when dry fly fishing silvers, getting that quick rise, following that with several casts to see what's what, and then going after another school if I get no offers. Others may have different opinions and better strategies, but this has worked for me.
Be warned that silvers often attack a dry fly from the rear -- like a shark. You can look right down their throats past the gill rakers as they come to the fly. Pretty exciting. Let the fish turn down with the fly before striking -- it's easy to pull the fly away from them.
Pink Pollywogs aren't the only dry flies to use, of course. Anything the size of a medium bass bug (popper) will probably work. Pink has been my favorite color, although fuchsia scores well. I make these critters out of deer hair on a No. 2 salmon dry fly hook (TULE light wire).
Hope this helps,
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