That looks somewhat like a fallfish, but I think it's something else. Fallfish are native to the East Coast, and I've caught them from New Jersey north into Maine.

I'm a little surprised that they would be native to Nebraska also, and further surprised why anyone would stock them outside of their native range.

I think the body is a little deep for a fallfish, and I don't thnk the mouth is quite right from what I can see. But the big, shiny scales are right on. Bottom line, related but something else.