The creek I mostly fish has a abundance of panfish, and a few trout and chub, but I've separated the creek into 2 major parts (after wading it for a mile and a half). The deeper down stream is where the bigger fish are, but I rarely see small minnows for them to feed on or any staple for them to "live" on. As I move about a 1/4 mile upstream it gets shallower and I see an abundance of smaller sunfish, minnows, and crawfish claws (on the shore) I wonder what the larger fish have to forage on. My main belief is that the deeper end has more of a muddy bottom, but the stream is just lined with rocks, so do the deeper fish have to forage more through the dirt and debris and also would the crawfish be moving upstream to blend in with the rocks because their backs are a bright red color (so they must be a target in the muddy water). If I can figure this out, I might just have a game plan.

It sounds like the forage upstream dies or gets weak, cant fight the current anymore and floats downstream to the bigger fish for them to feed on. Just a thought

It is a fact that you rarely see small and large fish together. The reason for this is that the small fish either run or become dinner!  Minnows probably drift or swim downstream, the reason you don't see them is that the larger fish saw them first! Tom

the ones downstream also probably eat bugs in the dirt