This is the Bluff road between Keithsburg and Seaton. This valley was formed by the most recent Ice Age that started about 2 million years ago and ended approximately 8000 B.C. When we were in high school and college it was not uncommon during exceedingly wet and rainy nights to have this whole road filled with live small frogs. It made driving an exercise in animal genocide, but it couldn't be helped.
Take the first right on the bluff and go down a ways to find an open area that overlooks the valley.
As stunning a view as you can find in these parts. Mrs. Olson, Seaton's 6th grade teacher always took her students to Bald Bluff Overlook. Not sure if this is it, but it would have been a similar view.