At the risk of starting another "viral" thread about Valley I am actually looking for information. As some of you know I have been fishing diverse locations for years but I have never encountered the schools of suckers I see in Valley. In some spots [mostly in the slow water] it looks like an underwater aircraft carrier with a hundred jets pointed into the wind. I know there are a few trout mixed in but when you cast even the smallest dry fly midge upstream from them the fish scatter like roaches when a light is turned on. Anybody have an answer as to why Valley appears [at least to me] to have a larger sucker population than most streams? Then again my observation might be totally wrong.

There are large populations of suckers in many streams.
There is also large populations of suckers fishing those streams.

There are a ton of them in Valley. They seem to be confined to areas that the trout don't care for, for the most part, however. I've never caught one there while targeting trout, though I have on other area streams.

Can't say on the population in Valley, but they're in a lot of trout streams, especially larger ones. They don't usually hold in the same type of water as trout though, especially once the water warms, so they're usually not an issue. In Winter they will share the same deep, slower holes though...this is when I tend to notice them more since I spend more time concentrating on these spots in Winter.

They may not be all Suckers either. Fallfish and Chubs, when looking at them from above in the water look (and behave) very similar to Suckers, and will often school in a similar fashion. I notice the same thing about them scattering when anything hits the surface as well.