I have a seen a fair amount of this grass along trails in Omaha, but I can't figure out what it is. I thought it was silver beardgrass (silver bluestem). But it's much too tall, and it isn't growing in clumps

Looks like possibly Miscanthus, or silvergrass

Looks like a Miscanthus to me too.

Yes, Miscanthus sinensis - Maiden Grass or Chinese Silver Grass.

This is an amazingly pestiferous plant here in Kentucky, escaping along the Mountain Parkway in eastern KY as well as along I-64 in central KY. I am still trying to kill off seedlings from a few parent plants that I landscaped with at the Valley 30 years ago.

On my current foray around the upper Midwest (Ohio, Michigan, Wisconsin, Minnesota, Iowa, Illinois, and Indiana) with Mrs. VV, I am seeing this plant in colonies in more than a few places. Depending on the length of the growing season, this could be a time bomb (a la Callery Pear) just waiting to go off.