I have an opportunity to take a flyfishing trip in late August to fish the Henry's Fork, South Fork of the Snake and I believe the Teton.

While I recognize these are world famous rivers, I'm just curious about how they fish during late August. Being from the Northeast I'm used to associating August with "dog days", with exception of a few tailwaters.

How is the dry fly action in late August?

Should I also assume that late August is one of the more crowded times of year?

Thanks in advance.

Zonk