Hi Steve,
You will have green drake and caddis hatchs when you are here for sure.
The above link to Taylor creek fly shop has a very accurate report updated weekly! In august you cannot beat a yellow stimmy. You should have some rusty spinners, all forms of caddis life in tan & olive, same for pmd's, bwo's , mysis and midges for the pan. We recently had a mud slide on the upper fork, it is in not coloring the water to bad. Only after rain should be o.k. by aug. I may be able to hook up to fish, maybe show you some less crowded water if you would like. I live 20 minutes up valley from bonedale.
Sheldon